Polypropylene ethylene-propylene copolymer blends and in-line process to produce them

ABSTRACT

Isotactic polypropylene ethylene-propylene copolymer blends and in-line processes for producing them. The blends may have between 1 and 50 wt % of isotactic polypropylene with a melt flow rate of between 0.5 and 20,000 g/10 min and a melting peak temperature of 145° C. or higher, and wherein the difference between the DSC peak melting and the peak crystallization temperatures is less than or equal to 0.5333 times the melting peak temperature minus 41.333° C., and between 50 and 99 wt % of ethylene-propylene copolymer including between 10 wt % and 20 wt % randomly distributed ethylene with a melt flow rate of between 0.5 and 20,000 g/10 min, wherein the copolymer is polymerized by a bulk homogeneous polymerization process, and wherein the total regio defects in the continuous propylene segments of the copolymer is between 40 and 150% greater than a copolymer of equivalent melt flow rate and wt % ethylene polymerized by a solution polymerization process.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/008,495 filed Dec. 20, 2007, herein incorporated by reference in itsentirety.

FIELD

The present invention relates to the field of polymer blends and in-lineprocesses to produce them. It more particularly relates to blends ofisotactic polypropylene and ethylene-propylene copolymer and in-linefluid phase processes for producing them.

BACKGROUND

Blends of highly crystalline isotactic polypropylene (iPP) and softethylene-propylene (EP) copolymers find many uses where flexibility andsoftness need to be combined with rapid crystallization for fastprocessing. These are iPP-EP blends produced at typically made bymelt-blending an iPP resin and an EP copolymer resin. The off-line meltblending process significantly increases the production cost since itinvolves two devolatilization-pelletization steps for the two blendingcomponents followed by melt-blending and pelletization of the finalproduct blend and also has many of the disadvantages associated withoff-line blending techniques.

Polymer blends may be made by a variety of ways. A flexible butexpensive off-line process of making polymer blends currently appliedfor making iPP-EP blends uses solid polymers as starting materials,typically outside the polymerization process that produced the polymerblend components. The polymer blend components are typically firstmelted or dissolved in a solvent and then blended. These processes areknown as melt-blending and off-line solution blending, respectively. Inmelt blending, the solid, often pelletized or baled, polymer blendcomponents are first melted and then blended together in their moltenstate. One of the difficulties presented by melt blending is the highviscosity of molten polymers, which makes blending of two or morepolymers difficult and often imperfect on the molecular level. Insolution off-line blending, the solid, often pelletized or baled,polymer blend components are first dissolved in a suitable solvent toform a polymer solution, and then two or more polymer solutions areblended together. After blending, solution blending requires the removalof solvent from the blend and drying of the blended polymer. Solutionblending can overcome the viscosity issue associated with melt blending,but is expensive due to the need for redissolving the polymer blendcomponents and due to the cost of solvent handling.

The common feature of both melt blending and off-line solution blendingis that the polymer blending components are made in separate plants andthe solid polymers then are reprocessed either in a molten or in adissolved state to prepare the final polymer blend. In fact, theseoff-line blending processes are often operated by so-called compounders,generally independent of the manufacturers of the polymer blendcomponents. These processes add considerable cost to the cost of thefinal polymer blend. The production and full polymer recovery inseparate plants and subsequent reprocessing increases the costs ofproducing such blends because of the need for duplicate polymer recoverylines and because of the need for separate blending facilities and theenergy associated with their operations. Off-line solution blending alsorequires extra solvent, and facilities for polymer dissolution andsolvent recovery-recycle. Substantial reprocessing costs could be savedif the polymer blends could be made in one integrated polymerizationplant in-line, i.e. before the recovery and pelletizing of the solidpolymer blend components.

The disadvantage of a separate polyolefin blending plant associated withthe melt blending and off-line solution blending processes is alleviatedwith the prior art method of in-line solution blending of polymers usinga series reactor configuration. Utilizing the series reactorconfiguration, product blending may be accomplished in the solutionpolymerization reactor itself when the effluent of the first solutionpolymerization reactor is fed into the second reactor operating atdifferent conditions with optionally different catalyst and monomer feedcomposition. Referring to the two-stage series reactor configuration ofFIG. 1 (prior art), the two different polymers made in the first andsecond reactor stages are blended in the second stage yielding a blendedpolymer product leaving the second reactor. Such reactor seriesconfiguration may be further expanded into more than a two-stage seriesconfiguration (three or more reactors in series). Generally, a series ofn reactors may produce a blend with as many as n components or even morepresent in the effluent of the last reactor. Note that in principle,more than n components may be produced and blended in n reactors by, forexample, using more than one catalyst or by utilizing multiple zonesoperating at different conditions in one or more reactors of the seriesreactor cascade. While mixing in the downstream reactor(s) provides goodproduct mixing, particularly when the reactors are equipped with mixingdevices, e.g., mechanical stirrers, such series reactor configurationand operation presents a number of practical process and product qualitycontrol problems due to the close coupling of the reactors in thecascade. One of the most important difficulties in commercial practiceis ensuring proper blend and monomer ratios to deliver consistent blendquality. Additional complications arise when the blend components havedifferent monomer compositions, particularly when they have differentmonomer pools, such as in the case of blending different copolymers orin the case of blending homo- and copolymers. Since the monomer streamsare blended, there is no option for their separate recovery and recyclemandating costly monomer separations in the monomer recycle lines.

Applying parallel reactors can overcome many of the disadvantagesrelated to the direct coupling of the polymerization reactors in anin-line polymer blending applying series reactors. While productionflexibility is increased, a parallel reactor arrangement necessitatesthe installation of blending vessels increasing the cost of the process.

A need thus exists for an improved and cost-effective method of in-lineblending of iPP and EP copolymers to avoid the issues associated withthe prior-art methods, such as melt blending, off-line solutionblending, and in-line solution blending in a series reactorconfiguration. More particularly, a need exists for an improved in-linemethod of blending iPP and EP copolymers, where the residence time,monomer composition, catalyst choice, and catalyst concentration can beindependently controlled in each polymer reactor prior to the blendingstep. There is also a need for improved blends of isotacticpolypropylene and ethylene-propylene copolymers that yield improvedproperties and performance in comparison to prior art blends of suchpolymers.

SUMMARY

Provided are blends of isotactic polypropylene and ethylene-propylenecopolymer and fluid-phase in-line blending process for producing suchblends.

According to the present disclosure, an advantageous in-line blendingprocess for producing blends of polypropylene and ethylene-propylenecopolymer comprises: (a) providing two or more reactor trains configuredin parallel and a high-pressure separator downstream fluidly connectedto the two or more reactor trains configured in parallel, wherein one ormore of the reactor trains produces polypropylene and one or more of thereactor trains produces ethylene-propylene copolymer; (b) contacting inone or more of the reactor trains configured in parallel 1) propylene,2) one or more catalyst systems, and 3) optional one or more diluents orsolvents, wherein the polymerization system for at least one of thereactor trains configured in parallel is at a temperature above thesolid-fluid phase transition temperature, at a pressure no lower than 10MPa below the cloud point pressure and less than 1500 MPa, contacting inthe other one or more reactor trains configured in parallel 1)propylene, 2) ethylene, 3) optional one or more comonomers comprisingfour or more carbon atoms, 4) one or more catalyst systems, and 5)optional one or more diluents or solvents, wherein at least one of thereactor trains is at a temperature of between 65° C. and 180° C. and ata pressure no lower than 10 MPa below the cloud point pressure of thepolymerization system and less than 1500 MPa, wherein the polymerizationsystem for each reactor train is in its dense fluid state and comprisespropylene, any ethylene present, any comonomer comprising four or morecarbon atoms present, any diluent or solvent present, and the polymerproduct, wherein the catalyst system for each reactor train comprisesone or more catalyst precursors, one or more activators, and optionally,one or more catalyst supports; and (c) forming a reactor effluentincluding a homogeneous fluid phase polymer-monomer mixture in eachparallel reactor train; (d) combining the reactor effluent comprisingthe homogeneous fluid phase polymer-monomer mixture from each parallelreactor train to form a combined reactor effluent; (e) passing thecombined reactor effluent through the high-pressure separator forproduct blending and product-feed separation; (f) maintaining thetemperature and pressure within the high-pressure separator above thesolid-fluid phase transition point but below the cloud point pressureand temperature to form a fluid-fluid two-phase system comprising apolymer-rich phase and a monomer-rich phase; (g) separating themonomer-rich phase from the polymer-rich phase to form apolymer-enriched stream comprising a blend of polypropylene andethylene-propylene copolymer and a separated monomer-rich stream, and(h) further processing the polymer enriched stream of (g) to furtherremove any solvent/diluent and/or monomer to yield apolypropylene-(ethylene-propylene copolymer) product blend.

A further aspect of the present disclosure relates to an advantageousin-line blending process for producing blends of polypropylene andethylene-propylene copolymer comprising: (a) providing two or morereactor trains configured in parallel and two or more high-pressureseparators fluidly connected to the two or more reactor trainsconfigured in parallel, wherein one or more of the reactor trainsproduces polypropylene and one or more of the reactor trains producesethylene-propylene copolymer; (b) contacting in one or more of thereactor trains configured in parallel 1) propylene, 2) one or morecatalyst systems, and 3) optional one or more diluents or solvents,wherein the polymerization system for at least one of the reactor trainsconfigured in parallel is at a temperature above the solid-fluid phasetransition temperature, at a pressure no lower than 10 MPa below thecloud point pressure and less than 1500 MPa, contacting in the other oneor more reactor trains configured in parallel 1) propylene, 2) ethylene,3) optional one or more comonomers comprising four or more carbon atoms,4) one or more catalyst systems, and 4) optional one or more solvents,wherein at least one of the reactor trains is at a temperature ofbetween 65° C. and 180° C. and at a pressure no lower than 10 MPa belowthe cloud point pressure of the polymerization system and less than 1500MPa, wherein the polymerization system for each reactor train is in itsdense fluid state and comprises propylene, any ethylene present, anycomonomer comprising four or more carbon atoms present, any diluent orsolvent present, and the polymer product, wherein the catalyst systemfor each reactor train comprises one or more catalyst precursors, one ormore activators, and optionally, one or more catalyst supports; and (c)forming an unreduced reactor effluent including a homogenous fluid phasepolymer-monomer mixture in each parallel reactor train; (d) passing theunreduced reactor effluents from one or more but not from all of theparallel reactor trains through one or more high-pressure separators,maintaining the temperature and pressure within the one or morehigh-pressure separators above the solid-fluid phase transition pointbut below the cloud point pressure and temperature to form one or morefluid-fluid two-phase systems with each two-phase system comprising apolymer-enriched phase and a monomer-rich phase, and separating themonomer-rich phase from the polymer-enriched phase in each of the one ormore high-pressure separators to form one or more separated monomer-richphases and one or more polymer-enriched phases; (e) combining the one ormore polymer-enriched phases from the one or more high-pressureseparators of (d) with the one or more unreduced reactor effluents fromone or more parallel reactor trains to form a mixture of one or morepolymer-enriched phases and the one or more unreduced reactor effluentsfrom the one or more parallel reactor trains to form a combined effluentstream that comprises the polymeric blend components from all parallelreactor trains; (f) passing the combined effluent stream of (e) intoanother high-pressure separator for product blending and product-feedseparation; (g) maintaining the temperature and pressure within theanother high pressure separator of (f) above the solid-fluid phasetransition point but below the cloud point pressure and temperature toform a fluid-fluid two-phase system comprising a polymer-rich blendphase and a monomer-rich phase; (h) separating the monomer-rich phasefrom the polymer-rich blend phase to form a polymer-enriched streamcomprising a blend of polypropylene and ethylene-propylene copolymer anda separated monomer-rich stream, and (i) further processing thepolymer-enriched stream of (h) to further remove any solvent/diluentand/or monomer to yield a polypropylene-(ethylene-propylene copolymer)product blend.

A still further aspect of the present disclosure relates to anadvantageous blend of isotactic polypropylene and ethylene-propylenecopolymer comprising: between 1 and 50 wt % of isotactic polypropylenewith a melt flow rate of between 0.5 and 20,000 g/10 min, and between 50and 99 wt % of ethylene-propylene copolymer including between 10 wt %and 20 wt % randomly distributed ethylene with a melt flow rate ofbetween 0.5 and 20,000 g/10 min, wherein the copolymer is polymerized bya bulk homogeneous polymerization process, and wherein the total regiodefects in the continuous propylene segments of the copolymer is between40 and 150% greater than a copolymer of equivalent melt flow rate and wt% ethylene polymerized by a solution polymerization process.

A still further aspect of the present disclosure relates to anadvantageous blend of isotactic polypropylene and ethylene-propylenecopolymer comprising: between 1 and 50 wt % of isotactic polypropylenewith more than 15 and less than 100 regio defects (sum of 2,1-erithro,2,1-threo insertions, and 3,1-isomerizations) per 10,000 propylene unitsin the polymer chain, an mmmm pentad fraction of 0.85 or more, a weightaverage molecular weight (Mw) of at least 35 kg/mol, a melting peaktemperature of 149° C. or higher, a heat of fusion (ΔHf) of at least 80J/g, and wherein the difference between the DSC peak melting and thepeak crystallization temperatures (Tmp−Tcp) is less than or equal to0.907 times the melting peak temperature minus 99.64 (Tmp−Tcp≦0.907Tmp−99.64)° C., and between 50 and 99 wt % of ethylene-propylenecopolymer including between 10 wt % and 20 wt % randomly distributedethylene with a melt flow rate of between 0.5 and 20,000 g/10 min.

A still yet further aspect of the present disclosure relates to anadvantageous blend of polypropylene and ethylene-propylene copolymercomprising: between 1 and 50 wt % of isotactic polypropylene with morethan 15 and less than 100 regio defects (sum of 2,1-erithro, 2,1-threoinsertions, and 3,1-isomerizations) per 10,000 propylene units in thepolymer chain, an mmmm pentad fraction of 0.85 or more, a weight averagemolecular weight (Mw) of at least 35 kg/mol, a melting peak temperatureof 149° C. or higher, a heat of fusion (ΔHf) of at least 80 J/g, andwherein the difference between the DSC peak melting and the peakcrystallization temperatures (Tmp−Tcp) is less than or equal to 0.907times the melting peak temperature minus 99.64 (Tmp−Tcp≦0.907Tmp−99.64)° C., and between 50 and 99 wt % of ethylene-propylenecopolymer including between 10 wt % and 20 wt % randomly distributedethylene with a melt flow rate of between 0.5 and 20,000 g/10 min,wherein the copolymer is polymerized by a bulk homogeneouspolymerization process, and wherein the total regio defects in thecontinuous propylene segments of the copolymer is between 40 and 150%greater than a copolymer of equivalent melt flow rate and wt % ethylenepolymerized by a solution polymerization process.

These and other features and attributes of the disclosed blends ofisotactic polypropylene and ethylene-propylene copolymers, the fluidphase in-line processes for producing them and their advantageousapplications and/or uses will be apparent from the detailed descriptionthat follows, particularly when read in conjunction with the figuresappended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist those of ordinary skill in the relevant art in making andusing the subject matter hereof, reference is made to the appendeddrawings, wherein:

FIG. 1 presents the process for the production of polymer blends in atwo-stage series reactor configuration (prior art);

FIG. 2 presents an exemplary in-line polymer blending process schematicfor producing isotactic polypropylene and ethylene-propylene copolymerblends with a single separation vessel;

FIG. 3 presents an exemplary in-line polymer blending process schematicfor producing isotactic polypropylene and ethylene-propylene copolymerblends with multiple separation vessels;

FIG. 4 presents an exemplary in-line polymer blending process schematicfor producing isotactic polypropylene and ethylene-propylene copolymerblends with product effluent buffer tanks for improved blend ratiocontrol;

FIG. 5 presents an exemplary in-line polymer blending process schematicwith product effluent buffer tanks that also serve as monomer/productseparators for improved blend ratio control;

FIG. 6 presents an exemplary in-line polymer blending process schematicfor producing isotactic polypropylene and ethylene-propylene copolymerblends with one slurry reactor train;

FIG. 7 presents an exemplary in-line polymer blending process schematicfor producing isotactic polypropylene and ethylene-propylene copolymerblends with optional buffer tanks for improved blend ratio control andwith the option for additive/polymer blending component;

FIG. 8 presents cloud point isotherms for Polymer Achieve™ 1635;

FIG. 9 presents cloud point isotherms for Polymer PP 45379 dissolved inbulk propylene;

FIG. 10 presents cloud point isotherms for Polymer PP 4062 dissolved inbulk propylene;

FIG. 11 presents cloud point isotherms for Polymer Achieve™ 1635dissolved in bulk propylene;

FIG. 12 presents cloud point isotherms for Polymer PP 45379 dissolved inbulk propylene;

FIG. 13 presents cloud point isotherms for Polymer PP 4062 dissolved inbulk propylene;

FIG. 14 presents a comparison of isopleths for PP 45379, Achieve™ 1635,and PP 4062 dissolved in bulk propylene;

FIG. 15 presents a comparison of isopleths for Achieve™ 1635 andliterature data as described in J. Vladimir Oliveira, C. Dariva and J.C. Pinto, Ind. Eng, Chem. Res. 29, 2000, 4627;

FIG. 16 presents a comparison of isopleths for PP 45379 and literaturedata as described in J. Vladimir Oliveira, C. Dariva and J. C. Pinto,Ind. Eng, Chem. Res. 29 (2000), 4627;

FIG. 17 presents a comparison of isopleths for PP 4062 and literaturedata as described in J. Vladimir Oliveira, C. Dariva and J. C. Pinto,Ind. Eng, Chem. Res. 29, 2000, 4627;

FIG. 18 presents a basic phase diagram for mixture of propylene monomerwith selected polymers (isotactic polypropylene—iPP, syndiotacticpolypropylene—sPP, atactic polypropylene—aPP, or propylene-ethylenecopolymer);

FIG. 19 presents a comparison of the density of supercritical propyleneat 137.7° C. with liquid propylene at 54.4° C.;

FIG. 20 presents an operating regime in accordance with the processdisclosed herein for a reactor operating in a single liquid phase;

FIG. 21 presents an operating regime in accordance with the processdisclosed herein for a reactor operating in a liquid-liquid phase;

FIG. 22 presents an operating regime in accordance with the processdisclosed herein for a gravity separator;

FIG. 23 presents supercooling versus melting peak temperature for theiPP blend component;

FIG. 24 depicts that turnover frequency is independent of catalystconcentration suggesting first kinetic order for catalyst insupercritical propylene polymerization with MAO-activated(μ-dimethylsilyl)bis(2-methyl-4-phenylindenyl)zirconium dichloride(Q-Zr-MAO) at 120-130° C. and 69 and 138 MPa (10 or 20 kpsi,respectively);

FIG. 25 presents a typical ¹³C NMR spectrum of an C₂ ⁼-C₃ ⁼ copolymerwith high ethylene content;

FIG. 26 presents the defects for an EP copolymer chain segment growingfrom left to right;

DEFINITIONS

For the purposes of this invention and the claims thereto:

A catalyst system is defined to be the combination of one or morecatalyst precursor compounds and one or more activators. Any part of thecatalyst system can be optionally supported on solid particles, in whichcase the support is also part of the catalyst system.

Fluids are defined as materials in their liquid or supercritical fluidstate. Dense fluids are defined as fluid media in their liquid orsupercritical state with densities greater than 300 kg/m³.

Solid-fluid phase transition temperature is defined as the temperatureat which a solid polymer phase separates from the polymer-containingdense fluid medium at a given pressure. The solid-fluid phase transitiontemperature can be determined by temperature reduction starting fromtemperatures at which the polymer is fully dissolved in the fluidreaction medium. Solid-fluid phase transition temperature can bemeasured by turbidity in addition to other known measurement techniques.

Solid-fluid phase transition pressure is defined as the pressure atwhich a solid polymer phase separates from the polymer-containing fluidmedium at a given temperature. The solid-fluid phase transition pressurecan be determined by pressure reduction at constant temperature startingfrom pressures at which the polymer is fully dissolved in the fluidreaction medium. Solid-fluid phase transition pressure can be measuredby turbidity in addition to other known measurement techniques.

The cloud point is defined as the pressure below which, at a giventemperature, the polymerization system becomes turbid as described in J.Vladimir Oliveira, C. Dariva and J. C. Pinto, Ind. Eng, Chem. Res. 29(2000) 4627. For purposes of this invention and the claims thereto, thecloud point is measured by shining a helium laser through the selectedpolymerization system in a cloud point cell onto a photocell andrecording the pressure at the onset of rapid increase in lightscattering (turbidity) for a given temperature.

A higher α-olefin is defined as an alpha-olefin having 4 or more carbonatoms.

Use of the term “polymerization” encompasses any polymerization reactionsuch as homopolymerization and copolymerization. Copolymerizationencompasses any polymerization reaction of two or more monomers.

The new numbering scheme for the Periodic Table Groups is used aspublished in CHEMICAL AND ENGINEERING NEWS, 63(5), 27 (1985).

When a polymer is referred to as comprising an olefin, the olefinpresent in the polymer is the polymerized form of the olefin.

An oligomer is defined to be compositions having 2-75 monomer units.

A polymer is defined to be compositions having 76 or more monomer units.

A series reactor cascade can include two or more reactors connected inseries, in which the effluent of an upstream reactor is fed to the nextreactor downstream in the reactor cascade. Besides the effluent of theupstream reactor(s), the feed of any reactor can be augmented with anycombination of additional monomer, catalyst, scavenger, or solvent freshor recycled feed streams. In a parallel reactor configuration, thereactor or reactors in series cascade that form a branch of the parallelreactor configuration is referred to as a reactor train.

Reactor train or reactor branch or reactor leg refers to a singlepolymerization reactor or to a group of polymerization reactors of thein-line blending process disclosed herein that produces a single polymerblend component. If the reactor train contains more than one reactor,the reactors are arranged in a series configuration within the train.The need for having more than one reactor in a reactor train may, forexample, arise when an in-line blend component cannot be produced at thedesired rate economically in a single reactor but there could be alsoreasons related to blend component quality, such as molecular weight orcomposition distribution, etc. Since a reactor train can comprisemultiple reactors and/or reactor zones in series, the single blendcomponent produced in a reactor train may itself be a polymer blend ofpolymeric components with varying molecular weights and/or compositions.However, in order to simplify the description of different embodimentsof the in-line blending processes disclosed herein, the polymericproduct of a reactor train is referred to simply as blend component orpolymeric blend component regardless of its molecular weight and/orcompositional dispersion. For the purpose of defining the process of thepresent invention, parallel reactors will be always considered asseparate reactor trains even if they produce essentially the samein-line blend component. Also, spatially separated, parallel reactionzones that do not exchange or mix reaction mixtures by, for example,pump-around loops, or by other recirculation methods, will be consideredas separate parallel reactor trains even when those parallel zones arepresent in a common shell and fall within the in-line blending processdisclosed herein.

Reactor bank refers to the combination of all polymerization reactors inthe polymerization section of the in-line polymer blending processdisclosed herein. A reactor bank may comprise one or more reactortrains.

A parallel reactor configuration includes two or more reactors orreactor trains connected in parallel. A reactor train, branch, or leg ofthe parallel configuration may include one reactor or more than onereactor configured in a series configuration. The entire parallelreactor configuration of the polymerization process disclosed herein,i.e., the combination of all parallel polymerization reactor trainsforms the reactor bank.

Monomer recycle ratio refers to the ratio of the amount of recycledmonomer fed to the reactor divided by the total (fresh plus recycled)amount of monomer fed to the reactor.

Polymerization system is defined to be monomer(s) plus comonomer(s) pluspolymer(s) plus optional inert solvent(s)/diluent(s) plus optionalscavenger(s). Note that for the sake of convenience and clarity, thecatalyst system is always addressed separately in the present discussionfrom other components present in a polymerization reactor. In thisregard, the polymerization system is defined here narrower thancustomary in the art of polymerization that typically considers thecatalyst system as part of the polymerization system. By the currentdefinition, the mixture present in the polymerization reactor and in itseffluent is composed of the polymerization system plus the catalystsystem. Dense fluid polymerization systems have greater than 300 kg/m³fluid phase density, all of their components listed above, i.e., themonomer(s) plus comonomer(s) plus polymer(s) plus optional inertsolvent(s)/diluent(s) plus optional scavenger(s), are in fluid state, orstating differently, none of their components is in solid state. Notethat these qualifications may be different for the catalyst system sinceit is not part of the polymerization system.

The polymerization system can form one single fluid phase or two fluidphases.

A homogeneous polymerization system contains all of its componentsdispersed and mixed on a molecular scale. In our discussions,homogeneous polymerization systems are meant to be in their dense fluid(liquid or supercritical) state. Note that our definition of thepolymerization system does not include the catalyst system, thus thecatalyst system may or may not be homogeneously dissolved in thepolymerization system. A homogeneous system may have regions withconcentration gradients, but there would be no sudden, discontinuouschanges of composition on a micrometer scale within the system. Inpractical terms, a homogeneous polymerization system has all of itscomponents in a single dense fluid phase. Apparently, a polymerizationsystem is not homogeneous when it is partitioned to more than one fluidphase or to a fluid and a solid phase. The homogeneous fluid state ofthe polymerization system is represented by the single fluid region inits phase diagram.

A homogeneous polymerization process operates with a homogeneouspolymerization system. Note that the catalyst system is not part of thepolymerization system, thus it is not necessarily dissolvedhomogeneously in the polymerization system. A reactor in which ahomogeneous polymerization process is carried out will be referred to ashomogeneous polymerization reactor.

Pure substances, including all types of hydrocarbons, can exist ineither a subcritical, or supercritical state, depending on theirtemperature and pressure. Substances in their supercritical statepossess interesting physical and thermodynamic properties, which areexploited in this disclosure. In particular, as supercritical fluidsundergo large changes in pressure, their density and solvency forpolymers changes over a wide range. To be in the supercritical state, asubstance must have a temperature above its critical temperature (Tc)and a pressure above its critical pressure (Pc). Mixtures ofhydrocarbons, including mixtures of monomers, polymers, and optionalsolvents, have pseudo-critical temperatures (Tc) and pseudo-criticalpressures (Pc), which for many systems can be approximated bymole-fraction-weighted averages of the corresponding critical properties(Tc or Pc) of the mixture's components. Mixtures with a temperatureabove their pseudo-critical temperature and a pressure above theirpseudo-critical pressure will be said to be in a supercritical state orphase, and the thermodynamic behavior of supercritical mixtures will beanalogous to supercritical pure substances. For purposes of thisdisclosure, the critical temperatures (Tc) and critical pressures (Pc)of certain pure substances relevant to the current invention are thosethat found in the HANDBOOK OF CHEMISTRY AND PHYSICS, David R. Lide,Editor-in-Chief, 82nd edition 2001-2002, CRC Press, LLC. New York, 2001.In particular, the Tc and Pc of various molecules are:

Pc Name Tc (K.) (MPa) Name Tc (K.) Pc (MPa) Hexane 507.6 3.025 Propane369.8 4.248 Isobutane 407.8 3.64 Toluene 591.8 4.11 Ethane 305.3 4.872Methane 190.56 4.599 Cyclobutane 460.0 4.98 Butane 425.12 3.796Cyclopentane 511.7 4.51 Ethylene 282.34 5.041 1-Butene 419.5 4.02Propylene 364.9 4.6 1-pentene 464.8 3.56 Cyclopentene 506.5 4.8 Pentane469.7 3.37 Isopentane 460.4 3.38 Benzene 562.05 4.895 Cyclohexane 553.84.08 1-hexene 504.0 3.21 Heptane 540.2 2.74 273.2 K. = 0° C.

The following abbreviations are used: Me is methyl, Ph is phenyl, Et isethyl, Pr is propyl, iPr is isopropyl, n-Pr is normal propyl, Bu isbutyl, iBu is isobutyl, tBu is tertiary butyl, p-tBu is para-tertiarybutyl, TMS is trimethylsilyl, TIBA is tri-isobutylaluminum, MAO ismethylaluminoxane, pMe is para-methyl, flu is fluorenyl, cp iscyclopentadienyl.

By “continuous” is meant a system that operates (or is intended tooperate) without interruption or cessation. For example a continuousprocess to produce a polymer would be one where the reactants arecontinually introduced into one or more reactors and polymer product iscontinually withdrawn.

The term “solvent”, or “high-boiling diluent” refers to a hydrocarbonhaving a boiling point of 30° C. or more, or 50° C. or more, or 70° C.or more, or 100° C. or more, or 120° C. or more, or 150° C. or more thanthe boiling point of propylene (−47.6° C. at 760 torr). High boilingdiluents are also referred to as solvents herein. In olefinpolymerization, solvents are typically hydrocarbons comprising five ormore carbon atoms.

Slurry polymerization refers to a polymerization process in whichparticulate, solid polymer (e.g., granular) forms in a dense fluid or ina liquid/vapor polymerization medium. The dense fluid polymerizationmedium can form a single or two fluid phases, such as liquid,supercritical fluid, or liquid/liquid, or supercriticalfluid/supercritical fluid, polymerization medium. In a liquid/vaporpolymerization medium, the polymer resides in the liquid (dense) phase.Slurry polymerization processes typically employ heterogeneous catalystparticles, such as Ziegler-Natta catalysts or supported metallocenecatalysts, and the like. The solid polymeric product typically adheresto the heterogeneous solid catalyst particles thus forming a slurryphase. Slurry polymerization processes operate below the solid-fluidphase transition temperature of the polymerization system.

Solution polymerization refers to a polymerization process in which thepolymer is dissolved in a liquid polymerization system comprisingsubstantial amounts (typically 40 wt % or more, or 50 wt % or more, or60 wt % or more) of solvent. Note that solution polymerization comprisesa liquid polymerization system. Solution polymerization may be performedat conditions where a vapor and a liquid phase are present, in whichcase the polymerization system comprises the liquid phase.

Advantageously, solution polymerization is performed with liquid-filledreactors, in the substantial absence of a vapor phase. Liquid-filledreactor operations are characterized by reactor pressures that are at oradvantageously above the bubble point of the polymerization system.Bubble point is defined as the pressure at which a liquid starts formingvapor bubbles at a given temperature. Bubble point pressures ofhydrocarbon blends can be readily determined by standard techniquesknown in the art of chemical engineering. Methods suitable forconducting such calculations are equation of state methods, such as PengRobinson or Suave Redlich Kwong. The bubble point of a liquid can beconveniently determined by reducing the pressure at constant temperatureof a compressed fluid until the first vapor bubble is formed. Solutionpolymerization is typically performed in a single homogeneous liquidphase, but solution polymerization comprising two liquid phases are alsoknown. In the latter case, the polymerization system is below of itscloud point pressure but above of its solid-fluid phase transitionpressure and temperature. In these two-phase liquid polymerizationssystems, the polymerization system is typically partitioned into twoliquid phases, a polymer-lean and a polymer-rich liquid phase. In awell-stirred polymerization reactor, these two phases are finelydispersed. Note, however, that these two-phase liquid polymerizationssystems have none of their components in solid state.

Supercritical polymerization refers to a polymerization process in whichthe polymerization system is in its dense supercritical or pseudosupercritical state, i.e. when the density of the polymerization systemis above 300 g/L and its temperature and pressure are above thecorresponding critical or pseudo critical values. Supercriticalpolymerization is typically performed in a single homogeneoussupercritical phase, but supercritical polymerization comprising twosupercritical fluid phases is also contemplated. In the latter case, thepolymerization system is below of its cloud point pressure but above ofits solid-fluid phase transition pressure and temperature. In thesetwo-phase supercritical fluid polymerizations systems, thepolymerization system is typically partitioned into two fluid phases, apolymer-lean and a polymer-rich fluid phase. In a well-stirredpolymerization reactor, these two phases are finely dispersed. Note,however, that these two-phase supercritical fluid polymerizationssystems have none of their components in solid state.

Bulk polymerization refers to a polymerization process in which thedense fluid polymerization system contains less than 40 wt %, or lessthan 30 wt %, or less than 20 wt %, or less than 10 wt %, or less than 5wt %, or less than 1 wt % of inert solvent or diluent. The productpolymer may be dissolved in the dense fluid polymerization system or mayform a solid phase. In this terminology, slurry polymerization, in whichsolid polymer particulates form in a dense fluid polymerization systemcontaining less than 40 wt % of inert solvent or diluent, will bereferred to as a bulk slurry polymerization process or bulkheterogeneous polymerization process. The polymerization process inwhich the polymeric product is dissolved in a single-phase dense fluidpolymerization system containing less than 40 wt % of inert solvent ordiluent will be referred to as bulk homogeneous polymerization process.The polymerization process in which the polymeric product is dissolvedin a liquid polymerization system containing less than 40 wt %, or lessthan 30 wt %, or less than 20 wt %, or less than 10 wt %, or less than 5wt %, or less than 1 wt % of inert solvent or diluent will be referredto as bulk solution polymerization process (as distinguished from othersolution polymerization processes in which the polymeric product isdissolved in a liquid polymerization system containing greater than orequal to 40 wt % solvent, which is also referred to herein as the priorart solution process). The polymerization process in which the polymericproduct is dissolved in a single-phase supercritical polymerizationsystem containing less than 40 wt %, or less than 30 wt %, or less than20 wt %, or less than 10 wt %, or less than 5 wt %, or less than 1 wt %of inert solvent or diluent will be referred to as bulk homogeneoussupercritical polymerization process.

Homogeneous supercritical polymerization refers to a polymerizationprocess in which the polymer is dissolved in a single-phase densesupercritical fluid polymerization medium, such as an inert solvent ormonomer or their blends in their supercritical state. As describedabove, when the supercritical fluid polymerization system contains lessthan 40 wt %, or less than 30 wt %, or less than 20 wt %, or less than10 wt %, or less than 5 wt %, or less than 1 wt % of inert solvent andthe polymer is dissolved in the dense supercritical fluid, the processis referred to as a bulk homogeneous supercritical polymerizationprocess. Homogeneous supercritical polymerization should bedistinguished from heterogeneous supercritical polymerizations, such asfor example, supercritical slurry processes, the latter of which isperformed in supercritical fluids but form solid polymer particulates inthe polymerization reactor. Similarly, bulk homogeneous supercriticalpolymerization should be distinguished from bulk solutionpolymerization, the latter of which is performed in a liquid as opposedto in a supercritical polymerization system. Note that by ourdefinitions, the catalyst system should not be considered in determiningwhether a polymerization process is homogeneous or not.

Fouling refers to accumulation and deposition of solid polymer in theinterior reactor volume and/or in its interconnected parts such as feedports, stirrer (for stirred reactors), etc. For crystalline polymers,the polymer tends to accumulate and deposit on the reactor interior bycrystallization on surfaces that are at or below the crystallizationtemperature of the polymer. Reactor fouling creates considerableoperational costs, including reduced production rates and increaseddowntime for cleaning.

Reaction zone refers to the interior of a polymerization reactor whereboth the catalyst system and the polymerization system are present andmixed intentionally. The reaction zone is defined as the reactorinterior filled with the mixed polymerization and catalyst systemsbetween the feed ports and the effluent ports. By “where both thecatalyst system and the polymerization system are present and mixedintentionally” we mean the space where the polymerization reaction isdesigned to take place and the polymer is designed to be present asopposed to spaces where no reaction is intended to happen and no polymeris intended to be present, such as the interior of the catalyst andmonomer feed ports, stirrer assembly, etc. Although the later spaces aredirectly coupled to the reaction zone, no polymer is intended to enterand no polymer is intended to be polymerized in those spaces.

An ethylene propylene random copolymer (also referred to herein as EPcopolymer, EP random copolymer and EP polyolefin elastomer) is definedas propylene-based polymer with random insertions of ethylene along thepropylene-based polymer backbone. This is to be distinguished fromethylene propylene block copolymers which have groups or blocks ofethylene inserted along the propylene-based polymer backbone.

An isotactic polypropylene homopolymer blend component (also referred toherein as iPP and isotactic polypropylene) is defined as propylene-basedpolymer with all methyl groups from the propylene monomer units locatedon the same side of the polymer. Isotactic polypropylene issemicrystalline and forms a helix configuration.

An in-line blending process disclosed herein refers to one where thepolymerization and the polymer blending processes are integrated in asingle process and at least one of the polymerization trains operatesunder solution or homogeneous supercritical conditions. Although in-lineblending processes typically employ polymerization trains using solutionor homogeneous supercritical polymerization systems, one or more of thepolymerization trains may employ slurry polymerization systems,particularly bulk slurry polymerization systems. When the polymerizationreactor bank includes one or more slurry polymerization trains, theeffluents of those slurry trains are always heated to dissolve thepolymer and are optionally pressurized before mixing them with theeffluents of other trains to enable fluid-phase mixing.

The isotactic polypropylene and EP copolymer blend disclosed hereinrefers to a mixture of isotactic polypropylene and EP copolymercomponents. The components are produced internally in the in-lineblending process and are mixed in the same process without recoveringthem in their solid state. Optionally, the in-line blends may alsocontain additives produced outside the invention process, such asplasticizers, UV stabilizers, antioxidants, etc., and off-line polymericadditives/modifiers in minor amounts, i.e., less than 50%, or less than40%, or less than 30%, or less than 20%, or less than 10%, or less than5%, or less than 1% by weight.

DETAILED DESCRIPTION

Disclosed herein are novel blends of isotactic polypropylene andethylene-propylene copolymer and in-line processes for blending suchpolymers.

In some embodiments, the polymerization reactor trains operate in adense fluid state (i.e., in homogeneous liquid phase or homogeneoussupercritical phase). In some other embodiments, at least one of thereactor trains configured parallel operates above the criticaltemperature and critical pressure of the polymerization system and thepolymerization system is homogeneous. In one or more embodiments, thepolymerization is carried out in a bulk homogeneous polymerizationsystem (i.e., in bulk homogeneous liquid phase or bulk homogeneoussupercritical phase).

As disclosed in U.S. Patent Application No. 60/876,193 filed on Dec. 20,2006, herein incorporated by reference in its entirety, an improvedin-line process for blending polymers has been developed to improveblend quality and reduce the capital and operating costs associated witha combined polymerization and blending plant. The present disclosureexpands the scope of U.S. Patent Application No. 60/876,193 to anin-line blending process with two or more parallel reactor trains forproducing novel blends of isotactic polypropylene and ethylene-propylenecopolymers.

U.S. Patent Application No. 60/905,247, filed on Mar. 6, 2007,incorporated herein in its entirety by reference, discloses novelrecycle methods for the unconverted monomers that emerge from theparallel reactor trains of the in-line fluid phase polymer blendingprocesses disclosed herein. In particular, the novel recycle methods areapplicable wherein each monomer component fed to a first group of one ormore reactor trains of the said in-line blending processes is alsopresent in the feed of a second group of one or more trains of the saidin-line blending processes. The processes disclosed in U.S. PatentApplication No. 60/905,247, filed on Mar. 6, 2007 afford a simpler andlower-cost monomer recycling by eliminating the need for the recovery ofthe individual recycle components.

U.S. Patent Application No. 60/993,647, filed on Sep. 13, 2007,incorporated herein in its entirety by reference, discloses a novelprocess for fluid phase in-line blending of plasticized polymers,wherein one or more of the plasticizers are produced in a reactor trainin parallel with the reactor train used to produce the one or morepolymers.

U.S. Patent Application No. 60/993,646, filed on Sep. 13, 2007,incorporated herein in its entirety by reference, discloses a novelprocess for in-line blending of off-line produced plasticizers andin-line produced polymers, wherein the one or more plasticizers are fedto the process after the polymer reactor train and while the basepolymer still has a substantial quantity of light components to form aplasticized polymer blend.

The blends of iPP and EP copolymer disclosed herein may include a noveliPP in terms of structure and properties in combination with aconventional EP copolymer or a novel EP in terms of structure andproperties. The blends of iPP and EP copolymer disclosed herein may alsoinclude a conventional iPP and a novel EP copolymer in terms ofstructure and properties. Hence a total of three novel blendcombinations based upon conventional and differentiated iPP and EPcopolymers are disclosed. The blends of conventional iPP andconventional EP represent the prior art.

In one form (conventional iPP/novel EP copolymer), the novel blend ofisotactic polypropylene and ethylene-propylene copolymer comprising:between 1 and 50 wt % of isotactic polypropylene with a melt flow rateof between 0.5 and 20,000 g/10 min, and between 50 and 99 wt % ofethylene-propylene copolymer including between 10 wt % and 20 wt %randomly distributed ethylene with a melt flow rate of between 0.5 and20,000 g/10 min, wherein the copolymer is polymerized by a bulkhomogeneous polymerization process, and wherein the total regio defectsin the continuous propylene segments of the copolymer is between 40 and150% greater than a copolymer of equivalent melt flow rate and wt %ethylene polymerized by a solution polymerization process.

In another form (novel iPP/conventional EP copolymer), the novel blendof isotactic polypropylene and ethylene-propylene copolymer comprising:between 1 and 50 wt % of isotactic polypropylene with more than 15 andless than 100 regio defects (sum of 2,1-erithro, 2,1-threo insertions,and 3,1-isomerizations) per 10,000 propylene units in the polymer chain,an mmmm pentad fraction of 0.85 or more, a weight average molecularweight (Mw) of at least 35 kg/mol, a melting peak temperature of 149° C.or higher, a heat of fusion (ΔHf) of at least 80 J/g, and wherein thedifference between the DSC peak melting and the peak crystallizationtemperatures (Tmp−Tcp) is less than or equal to 0.907 times the meltingpeak temperature minus 99.64 (Tmp−Tcp≦0.907 Tmp−99.64)° C., and between50 and 99 wt % of ethylene-propylene copolymer including between 10 wt %and 20 wt % randomly distributed ethylene with a melt flow rate ofbetween 0.5 and 20,000 g/10 min.

In yet another form (differentiated iPP/differentiated EP copolymer),the novel blend of polypropylene and ethylene-propylene copolymercomprising: between 1 and 50 wt % of isotactic polypropylene with morethan 15 and less than 100 regio defects (sum of 2,1-erithro, 2,1-threoinsertions, and 3,1-isomerizations) per 10,000 propylene units in thepolymer chain, an mmmm pentad fraction of 0.85 or more, a weight averagemolecular weight (Mw) of at least 35 kg/mol, a melting peak temperatureof 149° C. or higher, a heat of fusion (ΔHf) of at least 80 J/g, andwherein the difference between the DSC peak melting and the peakcrystallization temperatures (Tmp−Tcp) is less than or equal to 0.907times the melting peak temperature minus 99.64 (Tmp−Tcp≦0.907Tmp−99.64)° C., and between 50 and 99 wt % of ethylene-propylenecopolymer including between 10 wt % and 20 wt % randomly distributedethylene with a melt flow rate of between 0.5 and 20,000 g/10 min,wherein the copolymer is polymerized by a bulk homogeneouspolymerization process, and wherein the total regio defects in thecontinuous propylene segments of the copolymer is between 40 and 150%greater than a copolymer of equivalent melt flow rate and wt % ethylenepolymerized by a solution polymerization process.

In one form of the novel in-line process to produce such blends, theprocess includes providing two or more reactor trains configured inparallel and a high-pressure separator downstream fluidly connected tothe two or more reactor trains configured in parallel, wherein one ormore of the reactor trains produces polypropylene and one or more of thereactor trains produces ethylene-propylene copolymer. In one or more ofthe reactor trains configured in parallel 1) propylene, 2) one or morecatalyst systems, and 3) optional one or more diluents or solvents, arecontacted wherein the polymerization system for at least one of thereactor trains configured in parallel is at a temperature above thesolid-fluid phase transition temperature, at a pressure no lower than 10MPa below the cloud point pressure and less than 1500 MPa. In the otherone or more reactor trains configured in parallel 1) propylene, 2)ethylene, 3) optional one or more comonomers comprising four or morecarbon atoms, 4) one or more catalyst systems, and 5) optional one ormore diluents or solvents, are contacted wherein at least one of thereactor trains is at a temperature of between 65° C. and 180° C. and ata pressure no lower than 10 MPa below the cloud point pressure of thepolymerization system and less than 1500 MPa. The polymerization systemfor each reactor train is in its dense fluid state and comprisespropylene, any ethylene present, any comonomer comprising four or morecarbon atoms present, any diluent or solvent present, and the polymerproduct. The catalyst system for each reactor train comprises one ormore catalyst precursors, one or more activators, and optionally, one ormore catalyst supports. In each parallel reactor train is formed areactor effluent including a homogeneous fluid phase polymer-monomermixture. The reactor effluents comprising the homogeneous fluid phasepolymer-monomer mixture from each parallel reactor train are combined toform a combined reactor effluent. The combined reactor effluent is thenpassed through the high-pressure separator for product blending andproduct-feed separation. In the high pressure separator, temperature andpressure are maintained above the solid-fluid phase transition point butbelow the cloud point pressure and temperature to form a fluid-fluidtwo-phase system comprising a polymer-rich phase and a monomer-richphase. The monomer-rich phase is separated from the polymer-rich phaseto form a polymer-enriched stream comprising a blend of polypropyleneand ethylene-propylene copolymer and a separated monomer-rich stream forfurther processing to further remove any solvent/diluent and/or monomerto yield a polypropylene-(ethylene-propylene copolymer) product blend.

In another form of the novel in-line process to produce such blends, theprocess includes providing two or more reactor trains configured inparallel and two or more high-pressure separators fluidly connected tothe two or more reactor trains configured in parallel, wherein one ormore of the reactor trains produces polypropylene and one or more of thereactor trains produces ethylene-propylene copolymer. In one or more ofthe reactor trains configured in parallel 1) propylene, 2) one or morecatalyst systems, and 3) optional one or more diluents or solvents, arecontacted wherein the polymerization system for at least one of thereactor trains configured in parallel is at a temperature above thesolid-fluid phase transition temperature, at a pressure no lower than 10MPa below the cloud point pressure and less than 1500 MPa. In the otherone or more reactor trains configured in parallel 1) propylene, 2)ethylene, 3) optional one or more comonomers comprising four or morecarbon atoms, 4) one or more catalyst systems, and 4) optional one ormore solvents, are contacted wherein at least one of the reactor trainsis at a temperature of between 65° C. and 180° C. and at a pressure nolower than 10 MPa below the cloud point pressure of the polymerizationsystem and less than 1500 MPa. The polymerization system for eachreactor train is in its dense fluid state and comprises propylene, anyethylene present, any comonomer comprising four or more carbon atomspresent, any diluent or solvent present, and the polymer product. Thecatalyst system for each reactor train comprises one or more catalystprecursors, one or more activators, and optionally, one or more catalystsupports. An unreduced reactor effluent including a homogenous fluidphase polymer-monomer mixture is formed in each parallel reactor trainand is passed from one or more but not from all of the parallel reactortrains through one or more high-pressure separators. The temperature andpressure within the one or more high-pressure separators are maintainedabove the solid-fluid phase transition point but below the cloud pointpressure and temperature to form one or more fluid-fluid two-phasesystems with each two-phase system comprising a polymer-enriched phaseand a monomer-rich phase. The monomer-rich phase is separated from thepolymer-enriched phase in each of the one or more high-pressureseparators to form one or more separated monomer-rich phases and one ormore polymer-enriched phases. The one or more polymer-enriched phasesfrom the one or more high-pressure separators are combined with the oneor more unreduced reactor effluents from one or more parallel reactortrains to form a mixture of one or more polymer-enriched phases and theone or more unreduced reactor effluents from the one or more parallelreactor trains to form a combined effluent stream that comprises thepolymeric blend components from all parallel reactor trains. Thecombined effluent stream is then passed into another high-pressureseparator for product blending and product-feed separation where thetemperature and pressure are maintained above the solid-fluid phasetransition point but below the cloud point pressure and temperature toform a fluid-fluid two-phase system comprising a polymer-rich blendphase and a monomer-rich phase. The monomer-rich phase is separated fromthe polymer-rich blend phase to form a polymer-enriched streamcomprising a blend of polypropylene and ethylene-propylene copolymer anda separated monomer-rich stream. The polymer-enriched stream is thenfurther processed to further remove any solvent/diluent and/or monomerto yield a polypropylene-(ethylene-propylene copolymer) product blend.

In some embodiments, the polymerization is carried out in a densehomogeneous supercritical polymerization system, advantageously, in adense bulk homogeneous supercritical polymerization system.

For producing the novel iPP in-line blend components, homogeneouspropylene polymerization processes operating in a dense fluid state withelevated monomer concentrations (more than 2.5, or more than 3.0, ormore than 3.5, or more than 4.0, or more than 5.0, or more than 10.0mol/L in the reactor effluent) and reduced solvent concentrations (70 wt% or less, or 65 wt % or less, or 60 wt % or less, or 50 wt % or less,or 40 wt % or less in the reactor effluent) at temperatures above 90°C., or above 95° C., or above 100° C., or above 105° C., or above 110°C. and above 11 MPa, or above 13.8 MPa, or above 34.5 MPa using2,4-substituted bridged bisindenyl metallocene catalysts activated withnon-coordinating anion activators are particularly advantageous due tothe combination of good reactor stability and the ability to deliverhighly crystalline high MW isotactic polypropylenes.

The novel copolymer in-line blend components can be advantageouslyproduced in a solution or in a homogeneous supercritical polymerizationprocess. Increased monomer concentrations are sometimes advantageousbecause they afford higher MW/lower MFR products, or alternativelyafford the same MW at higher operating temperatures, and reduce theinert loads in the recycle loop thus can reduce the recycle and coolingcosts. When high polymer molecular weight is desired, the use of bulkhomogeneous polymerization processes, such as bulk solution or bulksupercritical polymerization is particularly advantageous.

The above-disclosed in-line blending processes also comprehend theoption for recycling the separated monomer-rich stream from theseparator(s) to the one or more of the reactor trains producingethylene-propylene copolymer, and thus eliminating the need forseparating mixed monomer and optional solvent streams before recyclingthem to the appropriate reactor trains for polymer.

In essence, the in-line blending processes disclosed herein comprise apolymerization section and at least one monomer-polymer separatorvessel, called the separator-blending vessel, or separator blender, orhigh-pressure separator. The separator-blending-vessel serves as both aseparator and a blender for the polymer-containing reactor effluents ofthe two or more parallel reactor trains in the reactor bank in which thetwo reactor trains employ a dense homogeneous fluid polymerizationsystem (i.e., defined as a homogeneous supercritical or a solutionpolymerization process). It is also beneficial to the proper operationof the in-line blending processes disclosed herein to bring thepolymerization system in each reactor train effluent into a homogeneousstate upstream of the separator-blending vessel. Therefore, when one ormore in-line blending components is/are produced in a particle-formingpolymerization process, such as, for example bulk propylene slurrypolymerization with Ziegler-Natta or supported metallocene catalysts,the so-produced solid polymer pellets need to be homogeneously dissolvedin the reactor effluent before entering the separator-blending vessel.This can be accomplished by, for example, pumping the reactor effluentslurry into a higher-temperature/higher-pressure dissolution zone thatbrings the reactor effluent above the solid-fluid phase transitiontemperature creating a stream in which the reaction product ishomogeneously dissolved.

The methods of fluid phase in-line polymer blending of iPP and EPcopolymer disclosed herein offer significant advantages relative toprior art methods of blending these polymers. One or more of theadvantages of the disclosed method of in-line iPP and EP copolymerblending include, but are not limited to, improved polymer blendhomogeneity because of molecular-level mixing of blend components,improved cost of manufacture because of savings from avoidance of thereprocessing cost associated with conventional off-line blendingprocesses that start with the separately produced solid, pelletizedpolymer blend components, and because of the ease and simplicity ofblending polymers at substantially reduced viscosities due to thepresence of substantial amounts of monomers and optionally solvents inthe blending step; flexibility of adjusting blend ratios and thereforeblend properties in-line; flexibility in adjusting production rates ofthe blend components; flexibility in independently controlling for eachreactor the residence time, monomer composition and conversion, catalystchoice, catalyst concentration, temperature and pressure; improved blendquality; flexibility in making a broader slate of iPP and EP copolymerblended products in the same plant; reduced process cost by utilizingthe monomer-polymer separator(s) for product blending and, in someembodiments, for product buffering to allow better control of blendratio.

The novel iPP and EP copolymer blends disclosed herein also yieldadvantageous properties including novel defect structures and higherpeak crystallization temperatures for a given peak melting point, whichallows for faster crystallization upon cooling during high speed polymerprocessing, such as the production. The novel iPP-EP copolymer blendsare also beneficial in applications requiring a combination of softnessand flexibility, for example, non-woven fabrics.

Conventional EP Copolymer Blend Component

The EP copolymer blend components may be conventional in composition andproperties, and made by supercritical, slurry or solution type process.For a description of conventional EP copolymers and conventional iPP-EPblends, refer to U.S. Pat. No. 6,642,316 and to S. Datta et al., RubberWorld 229 (2003) 55, which are included herein by reference in theirentirety. These conventional EP copolymer components may be in-lineblended with differentiated or novel isotactic polypropylene blendcomponents using the in-line blending processes disclosed herein to formnovel iPP-EP copolymer blends.

For a description of catalyst systems used to produce conventional EPcopolymers reference should be made to the following PCT patentpublications, all of which are included herein by reference: WO03/040095, WO 03/040201, WO 03/040202, WO 03/040233, WO 03/040442, andWO 04/041928. In addition, a description of conventional randompropylene polymers may be found in WO 03/040095, WO 03/040201, WO03/040202, WO 03/040233; WO 03/040442, and WO 04/041928, all of whichare included herein by reference. Moreover, additional catalyst systemsthat may be useful herein to produce polymers useful as random propylenepolymers and polymers useful as random propylene polymers include thosedescribed in Macromolecules, 2002, 35, 5742-5743, U.S. Pat. No.6,878,790, WO 02/055566 and WO 02/0246247, which are also includedherein by reference. An advantageous EP random copolymer used in thepresent invention is described in detail as the “Second PolymerComponent (SPC)” in co-pending U.S. applications U.S. Ser. No.60/133,966, filed May 13, 1999, and U.S. Ser. No. 60/342,854, filed Jun.29, 1999, and described in further detail as the “Propylene OlefinCopolymer” in U.S. Ser. No. 90/346,460, filed Jul. 1, 1999, which arefully incorporated by reference herein. Random copolymers of propyleneare available commercially under the trade name Vistamaxx™ (ExxonMobil,Baytown Tex.). Suitable examples include: Vistamaxx™ 6100, Vistamaxx™6200 and Vistamax™ 3000.

Novel/Differentiated EP Copolymer Blend Component

Described below is the composition, process for making, and propertiesof novel and differentiated EP copolymer blend components for use in thein-line produced iPP and EP copolymer blends disclosed herein.

In one form of the present disclosure, provided is an advantageouscontinuous process to produce a novel or differentiatedethylene-propylene random copolymer blend component that includes (a)providing one or more parallel reactor trains for producing EPcopolymer; (b) contacting in the reactors of the EP reactor train(s) 1)propylene monomer 2) one or more catalyst systems, 3) ethylenecomonomer, and 4) optional one or more solvents, wherein the reactortrain is at a temperature of between 65° C. and 180° C. and at apressure no lower than 10 MPa below the cloud point pressure of thepolymerization system and less than 1500 MPa, wherein the polymerizationsystem for the EP reactor train(s) is/are in its dense fluid state andcomprises the propylene monomer, the ethylene comonomer, any solventpresent, and the polymer product, wherein the polymerization systemcomprises less than 40 wt % of the optional solvent, and (c) forming apolymer reactor effluent including a homogeneous, fluid phasepolymer-monomer mixture in the reactor train; and wherein the resultantcopolymer product comprises between 10 wt % and 20 wt % randomlydistributed ethylene. The one or more catalyst systems for the reactortrain comprise one or more catalyst precursors, one or more activators,and optionally, one or more catalyst supports. The one or more catalystsystems are chosen from Ziegler-Natta catalysts, metallocene catalysts,nonmetallocene metal-centered, heteroaryl ligand catalysts, latetransition metal catalysts, and combinations thereof.

The one reactor or the two or more serially configured reactors (alsoreferred to herein as a reactor train) in which the bulk homogenouspolymerization process occurs to produce the EP copolymer blendcomponent may be chosen from tank type, loop type, tubular type andcombinations thereof. When utilizing two or more serially configuredreactors, a tubular reactor followed by a continuous stirred tankreactor or a tubular reactor followed by a loop reactor may beadvantageous. In one form of the disclosed bulk polymerization processesfor producing EP random copolymer blend components disclosed herein, thereactor train operates above the critical or pseudo-critical temperatureand critical or pseudo-critical pressure of the polymerization system.

In another form, the disclosed polymerization process for producing EPrandom copolymer blend components operate at high monomerconcentrations. Non-limiting exemplary monomer concentrations aregreater than 2.0 mol/L, advantageously greater than 2.5 mol/L, orgreater than 3.0 mol/L, or greater than 5 mol/L in the polymerizationreactor, or in its effluent. Some forms operate with substantially neatmonomer feeds, i.e. a bulk homogeneous polymerization system. Such bulkmonomer feeds may yield higher monomer concentrations in the reactor.Non-limiting exemplary monomer concentrations in the reactor are lessthan or equal to 10 mol/L, or less than or equal to 12 mol/L, or lessthan or equal to 13 mol/L, or less than or equal to 14 mol/L, or lessthan or equal to 15 mol/L, or less than or equal to 16 mol/L, or lessthan or equal to 18 mol/L. Further details of bulk homogeneouspolymerization systems are disclosed in U.S. Patent Application Nos.60/876,193 and No. 60/905,247, herein incorporated by reference in theirentirety.

Non-limiting exemplary process pressures utilized for making EP randomcopolymer blend components using the bulk homogeneous polymerizationprocess disclosed herein are from 2 to 40 kpsi (138-2759 bar), or 2 to15 kpsi (138-1034 bar), or 2 to 20 kspi (138-1379 bar), or 3 to 15 kpsi(207-1034 bar), or 5 to 15 kpsi (345-1034 bar). Non-limiting exemplarylower pressure limits for making the EP random copolymer blendcomponents disclosed herein are 2, or 3, or 4, or 5, or 7, or 10 kpsi(138, 207, 276, 345, 483, or 690 bar, respectively). Non-limitingexemplary upper pressure limits for making EP random copolymer blendcomponent are 5, or 7, or 10, or 15, or 20, or 30, or 40 kpsi (345, 483,690, 1379, 2069, or 2759 bar, respectively).

Non-limiting exemplary process temperature ranges for making the EPrandom copolymer blend components disclosed herein are 65 to 180° C., or65 to 140° C, or 70 to 180° C, or 75 to 150° C, or 80 to 150° C, or 80to 140° C., or 90 to 135° C., or 100 to 130° C., or 110 to 125° C.Non-limiting exemplary lower temperature limits for making the EP randomcopolymer blend components disclosed herein are 65, or 70, or 75, or 80,or 85, or 90, or 100, or 110° C. Non-limiting exemplary uppertemperature limits for making the EP random copolymers disclosed hereinare 180, or 160, or 150, or 140, or 135, or 130, or 125° C. Noteworthyis that the process temperature ranges of the bulk homogenouspolymerization process for making EP random copolymer blend componentsdisclosed herein are significantly higher than the temperature ranges ofthe prior art solution processes, which typically do not exceed 90° C.

Non-limiting exemplary compositions on an ethylene/(ethylene+propylene)basis (i.e., pure monomer basis) in the feed to the reactor making theEP random copolymer blend components disclosed herein range from 2 to 15wt %, or 2 to 12 wt %, or 3 to 12 wt %, depending on the ethyleneconcentration of the desired iPP-EP copolymer product. Non-limitingexemplary compositions on an ethylene/(ethylene+propylene) basis, i.e.,pure monomer basis in the effluent of the reactor making the EP randomcopolymer blend components disclosed herein may range from 0.5 to 10 wt%, or 1 to 10 wt %, or 1 to 8 wt %, or 2 to 8 wt %, depending on theethylene concentration of the desired iPP-EP copolymer blend product.Non-limiting exemplary propylene conversions in a single pass throughthe reactor making the EP random copolymer blend components disclosedherein may range from 5 to 35%, or 5 to 30%, or 5 to 25%, or 7 to 25%,or 10 to 25%.

The ethylene conversion for a given feed composition and propyleneconversion is governed by the ethylene/propylene reactivity ratio,defined as the ethylene/propylene molar ratio in the product divided bythe ethylene/propylene molar ratio in the reactor. Theethylene/propylene reactivity ratio for the bulk homogeneouspolymerization processes for producing EP random copolymer blendcomponents disclosed herein may range from 1.3 to 6, or 1.5 to 5, or 2to 5, and may be determined by analyzing the monomer composition of thepolymerization system and the product. The former can be accomplished byanalyzing the reactor content or the reactor feed and effluent bystandard gas chromatographic methods. The latter can be performed byusing ¹³C nuclear magnetic resonance (¹³C NMR) or infrared (IR)spectroscopy, as described later in the examples.

The bulk homogeneous polymerization processes for producing EP randomcopolymer blend components disclosed herein produce one or moreadvantages relative to the prior art solution processes. For example,prior art solution processes typically utilize 60 wt % or more, or 70 wt% or more, or 80 wt % or more inert solvent to keep the product polymerin a homogeneous dissolved state, to absorb reaction heat, and to keepviscosity low. However, such high inert solvent concentrations utilizedin solution processes lower the monomer concentration in the reactor toless than 2.0 mol/L, or less than 1.5 mol/L, or less than 1.0 mol/L, oreven less than 0.5 mol/L in the reactor and/or in its effluent. Thelower monomer concentration in turn necessitates lowering the reactortemperature to deliver the desired product molecular weight required toachieve the desired melt flow rate related to melt viscosity. Asmentioned before, maintaining lower reactor temperatures requires higherrefrigeration capacity, which increases both the capital investment andthe operation cost. In contrast, the disclosed bulk homogeneouspolymerization processes for producing EP random copolymer blendcomponents operate with high monomer concentrations (combined propylenemonomer and ethylene comonomer), for example, greater than 2.0 mol/L,advantageously greater than 2.5 mol/L, or 3.0 mol/L, or 5.0 mol/L, or8.0 or 10.0 mol/L in the polymerization reactor, and/or in its effluent.The combined propylene monomer and ethylene comonomer present in thecombined feed to the reactor may be 40, or 50, or 60, or 75 wt % ormore. These higher monomer concentrations in the polymerization reactorenables the production of EP random copolymer blend component atincreased reactor temperatures allowing the reduction of capitalinvestment and operation cost for the process.

The bulk homogeneous polymerization processes for producing EP randomcopolymer blend components disclosed herein operate with a bulkhomogeneous polymerization system, such as bulk solution polymerizationand bulk homogeneous supercritical polymerization. These processessubstantially utilize the monomer as a solvent in order to keep thepolymer in a homogeneous dissolved state, to reduce viscosity, and toabsorb the heat of reaction. For the bulk homogeneous polymerizationprocesses for producing EP random copolymer blend components disclosedherein, the reactor system may have monomer concentrations (propyleneand ethylene) of less than or equal to 12 mol/L, or less than or equalto 13 mol/L, or less than or equal to 14 mol/L, or less than or equal to15 mol/L, or less than or equal to 16 mol/L, or less than or equal to 18mol/L. Small quantities of inert solvents/diluents may also beoptionally present, but are advantageously a minority component in thereactor feed, and thus in the reactor. Hence, the total combinedconcentration of inert solvents for the bulk homogeneous polymerizationprocesses for producing EP random copolymer blend components disclosedherein is typically is less than 60%, or less than 50%, or less than40%, or less than 30%, or less than 25%, or less than 20%, or less than15%, or less than 10% on a weight basis.

Some inert solvent components having more than three carbon atoms may beadded intentionally to the disclosed processes to function as solventaids in small concentrations, but advantageously the disclosed processesuse no such inert solvent in order to function as a solvent in thepolymerization system. Inert solvents/diluents, however, may be presentin the polymerization system disclosed herein due to build-up of inertcomponents, like propane and ethane, present in the monomer feed. Suchinert solvents/diluents may also originate from the catalyst feedsolution. As it will be appreciated by those skilled in the art, thesecomponents are present in the polymerization system fortuitously, i.e.,as an unavoidable component of a feed stream but not with the intent ofusing their polymer solvating properties in the reactor itself.Advantageously, the concentration of inert solvents having more thanthree carbon atoms typically used as solvents in the bulk homogeneouspolymerization processes for producing EP random copolymer blendcomponent disclosed herein is less than 40 wt %, or less than 30 wt %,or less than 20 wt %, or 15 wt % , or less than 10 wt %, or less than 5wt %, or less than 2 wt %, or less than 1 wt %, or less than 0.5 wt %,or less than 0.1 wt %, or less than 0.01 wt % (also defined assubstantially free of inert solvent) in the combined reactor feed (i.e.,the total of fresh and recycle feed), or in the polymerization system inthe reactor, or in the polymerization system leaving the reactor.Advantageously, the disclosed bulk homogeneous polymerization processesfor producing EP random copolymer blend components disclosed hereinoperate in a polymerization system that is substantially free of inertsolvents/diluents having more than three carbon atoms, thus operatewithout a dedicated solvent recycle and handling loop, which reducesplant capital investment and operating costs.

The higher monomer concentrations provided by the bulk homogeneouspolymerization processes for producing EP random copolymer blendcomponents disclosed herein also advantageously provides for increasedmolecular weight of the EP random copolymer component at otherwisesimilar reactor conditions. In such embodiments, the reaction conditionsare similar to those used in the prior art solution processes, but theproducts are of higher molecular weight affording lower melt flow rateswhile making EP copolymers with the same ethylene content.

In yet other embodiments, the disclosed bulk homogeneous polymerizationprocesses for making random EP copolymer blend components with 10 to 20wt % ethylene content are operated at 15 to 30° C., or 20 to 30° C., or25 to 30° C. higher polymerization temperatures than the prior artsolution process for producing EP copolymers with the same ethyleneconcentration and melt flow rate (MFR). The higher operating temperaturealso creates a novel combination of ethylene concentration, melt flowrate, and polymer microstructure as determined by the total regio defectconcentration in the continuous propylene segments measured by ¹³C NMR.The bulk homogeneous polymerization processes for producing EP randomcopolymer blend components disclosed herein typically yield EP randomcopolymers with a 40 to 150% or 40 to 100% higher total regio defectconcentration in the continuous propylene segments than the total regiodefect concentration found in random EP copolymers of comparableethylene content and melt flow rate made in prior art solutionprocesses.

The combination of higher monomer concentration and higher operatingtemperatures provided by the disclosed bulk homogeneous polymerizationprocesses, also provide significant increases in catalytic activity. Inparticular, catalytic activities for the disclosed bulk homogeneouspolymerization processes, measured in turnover frequency (TOF),expressed as mole of monomers converted per mol catalytic metal persecond, are 2 to 20 times, or 5 to 20 times, or 2 to 10 times or 3 to 10times higher than prior art solution processes producing EP randomcopolymers with comparable ethylene concentration and melt flow rate.The higher catalytic activities of the disclosed bulk homogeneouspolymerization processes in turn allows for smaller reactors, i.e.,lower residence times, and/or lower catalyst concentrations and thuslower catalyst costs for making products with comparable ethyleneconcentration and melt flow rate. The optimum combination of reductionin reactor volume and/or reduction in catalyst usage may be determinedby standard chemical engineering techniques.

Non-limiting exemplary reactor residence times for the disclosed bulkhomogeneous polymerization processes are from 2 to 30 minutes, or 2 to20 minutes, or 2 to 15 minutes, or 4 to 15 min, or 4 to 10 min. Thisreduced residence time also allows for a reduction in reactor size.Alternatively, or in combination thereof, the catalyst cost can bereduced by lowering the catalyst usage per unit polymer production withthe disclosed bulk homogeneous polymerization processes.

In addition to propylene monomer and ethylene comonomer feeds to thereactor system, other comonomers may also be optionally fed to thereactors. Non-limiting exemplary optional comonomers include butene-1,pentene-1, hexene-1, octene-1, decene-1, dodecene-1, and combinationsthereof. These optional comonomers may be incorporated into the EPcopolymer blend component at from 0.5 to 10 mol %, or from 0.5 to 8 mol%, or 1 to 5 mol %. This allows for ethylene-propylene terpolymerproducts to be produced.

In another form of the present disclosure, provided are advantageousrandom ethylene-propylene copolymer blend components comprising between10 wt % and 20 wt % randomly distributed ethylene with a melt flow rateof between 0.5 and 20,000 g/10 min, wherein the copolymer is polymerizedby a bulk homogeneous polymerization process, and wherein the totalregio defects in the continuous propylene segments of the copolymer isbetween 40 and 150% greater than a copolymer of equivalent melt flowrate and wt % ethylene polymerized by a solution polymerization process.

The bulk homogeneous polymerization processes for producing EP randomcopolymer blend components disclosed herein may produce copolymers withethylene contents as measured by ¹³C NMR or IR methods (described indetail in the examples) ranging from 10 to 20 wt %, or 10 to 18 wt %, or10 to 16 wt %. The bulk homogeneous polymerization processes forproducing EP random copolymer blend components disclosed herein mayproduce copolymers with melt flow rates as measured by ASTM D1238 or ISO1133 methods ranging from 0.5 to 20,000 g/10 min, or 0.5 to 5,000 g/10min, or 1.0 to 2,000 g/10 min, or 1.0 to 1500 g/10 min. The total regiodefect concentration in the continuous propylene segments of the EPrandom copolymer blend components produced using the bulk homogeneouspolymerization process disclosed herein may be greater than 0.50 mol %,or greater than 0.55 mol %, or greater than 0.60 mol %, or greater than0.65 mol %, or greater than 0.70 mol %. The analytical method formeasuring the regio defect concentration is by ¹³C NMR as described inthe examples in detail. As previously described, the EP random copolymerblend components disclosed herein may have a total regio defectconcentration in the continuous propylene segments which is 40 to 150%higher, or 40 to 100% higher than the total regio defect concentrationof EP copolymers of comparable ethylene content and melt flow rateproduced in prior art solution processes. When measurable amount ofcrystallinity is present in the random EP copolymers made by thedisclosed processes, their melting peak temperature as measured bydifferential scanning calorimetry or DSC (for the details of the DSCmethod see examples) may range from 35 to 80° C., or 40 to 70° C., or 45to 60° C. When an optional comonomer chosen from butene-1, pentene-1,hexene-1, octene-1, decene-1, dodecene-1 and combinations thereof areadded to the reactor feed stream, a propylene based random terpolymerproduct may be formed.

The detailed description below sets forth the details of the bulkhomogenous polymerization processes (bulk homogeneous supercriticalprocess and bulk solution process) where the processes and reactorspreviously described for producing the novel EP random copolymer blendcomponents disclosed herein are utilized. The advantageous processes forproducing the EP random copolymer blend components disclosed hereininclude reactors that operate with a bulk homogeneous dense fluid phase.Polymerization processes that operate in a homogenous dense fluid phaseuse either inert solvents or the monomers or their mixtures as a solventin their liquid or supercritical state. Hence, the one or more reactorsdisclosed herein operate with polymerization systems in theirhomogeneous supercritical or in their liquid state. The bulkpolymerization processes disclosed herein also operate with less than40%, or less than 30%, or less than 20 wt % or less than 10 wt % or lessthan 5 wt % of inert solvent present in the reactor, and in someembodiments, with less than 1 wt % of inert solvent. In one embodimentof the disclosed process, the reactors operate at bulk homogeneoussupercritical conditions as has been disclosed in U.S. patentapplication Ser. Nos. 11/433,889 and 11/177,004, herein incorporated byreference in their entirety.

Novel/Differentiated EP Copolymer Homogeneous Polymerization ProcessDetails:

In one or more embodiments for producing the novel EP copolymer blendcomponents, the process includes contacting, in a polymerization system,a propylene monomer, an ethylene comonomer with a catalyst, anactivator, optional other comonomer (advantageously butene-1, hexene-1,or octene-1, or decene-1, or dodecene-1, or combinations thereof), andoptionally inert solvent, at a temperature at or above 65° C., or 70°C., or 75° C., or 80° C., or 85° C., or 90° C., or 100° C., or 110° C.,and at a pressure above 1.5 kpsi (103 bar, 10.3 MPa), or above 2 kpsi(138 bar, 13.8 MPa), or above 5 kpsi (345 bar, 34.5 MPa), or above 10kpsi (690 bar, 69 MPa). The polymerization takes place in a bulkhomogeneous polymerization system within the reactor.

In one or more embodiments, the density of the polymerization system isabout 0.3 g/mL or more. In one or more embodiments, the density of thepolymerization system is about 0.4 g/mL or more. In one or moreembodiments, the density of the polymerization system is about 0.5 g/mLor more. In one or more embodiments, the density of the polymerizationsystem is about 0.6 g/mL or more. In one or more embodiments, thedensity of the polymerization system is of from 0.3 g/mL to 0.75 g/mL orfrom 0.30 to 0.70 g/mL.

In one or more embodiments, the steady state polymer yield (i.e.,conversion of monomer to polymer product) per pass is at least 5 wt % ofthe total combined monomer fed to the reactor. In one or moreembodiments, the conversion of monomer to polymer product in a singlepass is at least 10 wt % of the monomer. In one or more embodiments, theconversion of monomer to polymer product in a single pass is at least 20wt % of the monomer. In one or more embodiments, the conversion ofmonomer to polymer product in a single pass is at least 30 wt % of themonomer. In one or more embodiments, the conversion of monomer topolymer product in a single pass is at least 40 wt % of the monomer. Inone or more embodiments, the conversion of monomer to polymer product ina single pass is at least 50 wt % of the monomer. In one or moreembodiments, the conversion of monomer to polymer product in a singlepass is at least 60 wt % of the monomer. In one or more embodiments, theconversion of monomer to polymer product in a single pass is at least 70wt % of the total combined monomer fed to the reactor.

In one or more embodiments, the polymerization conditions are sufficientto keep the polymer product dissolved in the monomers present in theliquid state (i.e., “bulk solution polymerization”). In one or moreembodiments, the polymerization conditions are sufficient to keep thepolymer product dissolved in the monomers present in the densesupercritical fluid state (i.e., “bulk supercritical polymerization”).In one or more embodiments, the polymerization conditions are sufficientto form a single homogeneous dense fluid polymerization systemcomprising the monomers and less than 40 wt % inert solvent (i.e., bulkhomogeneous supercritical or bulk homogeneous solution polymerization).In one or more embodiments, the: critical or pseudo-critical temperatureand pressure of the reactor blends are different from the criticalvalues of the pure components, and thus supercritical operations attemperatures lower than the critical temperature of one or more of thepure monomers (e.g., 92° C. for propylene) are possible. In one or moreembodiments, near-amorphous materials with low melting points as well asamorphous materials can be produced without fouling even below thecritical temperature of the reactor blends, i.e., at temperatures thatcorrespond to the condensed liquid state of the polymerization system inthe reactor. In these instances, the operating temperature can be belowthe bubble-point of the reaction mixture and thus the reactor canoperate at what is often referred to as liquid-filled conditions. Insome instances, such operation mode could be desired to achieve highmolecular weight (MW) and thus low melt flow rate (MFR), particularly inthe manufacture of the EP random copolymers disclosed herein.

In one or more embodiments, the reaction temperature and pressure can beselected so that the polymerization system remains at a pressure belowthe polymer's cloud point in the particular polymerization system,resulting in a two-phase polymerization system comprising a polymer-richphase and a polymer-lean phase. Some embodiments that are below thepolymer's cloud point nonetheless operate above the polymer'scrystallization temperature.

In one or more embodiments, the polymerization temperature is above thecloud point of the polymerization system at the reactor pressure. Moreadvantageously, the temperature is 2° C. or more above the cloud pointof the polymerization system at the reactor pressure.

Non-limiting exemplary process temperature ranges for making the novelEP random copolymers disclosed herein are 65 to 180° C., or 65 to 140°C., or 70 to 180° C., or 75 to 150° C., or 80 to 150° C., or 80 to 140°C. or 90 to 135° C., or 100 to 130° C., or 110 to 125° C. Non-limitingexemplary lower temperature limits for making the EP random copolymersdisclosed herein are 65, or 70, or 75, or 80, or 85, or 90° C., or 100°C., or 110° C. Non-limiting exemplary upper temperature limits formaking the EP random copolymers disclosed herein are 180, or 160, or150, or 140, or 135, or 130, or 125° C.

In another embodiment, the temperature is between 65 and 180° C.,between 65 and 140° C., between 70 and 180° C., between 75 and 150° C.,between 80 and 150° C., or between 80 and 140° C. In another embodiment,the temperature is at or above 65, or 70, or 75, or 80, or 85, or 90°C., or 100° C., or 110° C. In another embodiment, the temperature is ator below 180, or 160, or 150, or 140, or 135, or 130, or 125° C., In oneor more embodiments, the polymerization temperature is from 65° C. to180° C. In one or more embodiments, the polymerization temperature isabout 70° C. to about 180° C. In one or more embodiments, thepolymerization temperature is 75° C. to 150° C. In one or moreembodiments, the polymerization temperature is about 40° C. to about105° C. In one or more embodiments, the polymerization temperature is80° C. to 150° C. In one or more embodiments, the polymerizationtemperature is 80° C. to 140° C.

In one or more embodiments, the polymerization temperature is above thefluid-solid phase transition temperature (sometimes referred to ascrystallization temperature) of the polymerization system at the reactorpressure. Advantageously, the temperature is at least 2° C. or at least5° C. above the fluid-solid phase transition temperature of thepolymerization system at the reactor pressure. More advantageously, thetemperature is at least 10° C. above the fluid-solid phasetransformation point of the polymerization system at the reactorpressure.

In one or more embodiments, the polymerization pressure is above thefluid-fluid phase transition pressure of the polymerization system atthe reactor temperature, i.e., the reactor operates with a homogeneousdense fluid polymerization system. In one or more embodiments, thepolymerization pressure is no lower than 10 MPa (100 bar) below, or nolower than 5 MPa (50 bar) below, or no lower than 2 MPa (20 bar) below,or no lower than 1 MPa (10 bar) below, or no lower than 0.1 MPa (1 bar)below, or no lower than 0.01 MPa (0.1 bar) below the cloud point of thepolymerization system at the reactor temperature.

Novel/Differentiated EP Copolymer Blend Component Monomer andComonomers:

Propylene monomer and ethylene comonomer are fed to the reactor(s) ofthe bulk homogeneous polymerization processes disclosed herein. Thepropylene monomer may have a purity of greater than 99 wt %, or greaterthan 99.5 wt % or greater than 99.9 wt %. The ethylene comonomer mayhave a purity of greater than 99 wt %, or greater than 99.5 wt % orgreater than 99.9 wt %.

In one or more embodiments, one or more optional comonomers, in additionto the ethylene comonomer, may be fed to the reactor. For example, C₄ toC₁₂ aliphatic olefins, such as butenes, pentenes, hexenes, heptenes,octenes, nonenes, decenes, undecenes, and dodecenes, oraromatic-group-containing comonomers containing up to 30 carbon atomscan be used. Suitable aromatic-group-containing comonomers comprise atleast one aromatic structure, advantageously from one to three, moreadvantageously a phenyl, indenyl, fluorenyl, or naphthyl moiety. Thearomatic-group-containing comonomer further comprises at least onepolymerizable double bond such that after polymerization, the aromaticstructure will be pendant from the polymer backbone. Thearomatic-group-containing comonomer can further be substituted with oneor more hydrocarbyl groups including but not limited to C₁ to C₁₀ alkylgroups. Additionally two adjacent substitutions can be joined to form aring structure. Advantageous aromatic-group-containing comonomerscontain at least one aromatic structure appended to a polymerizableolefinic moiety. Particularly advantageous aromatic comonomers includestyrene, alpha-methylstyrene, para-alkylstyrenes, vinyltoluenes,vinylnaphthalene, allyl benzene, and indene, especially styrene,paramethyl styrene, 4-phenyl-butene-1 and alkylbenzene.

In one or more embodiments, non-aromatic cyclic group containingcomonomers can be used. These comonomers can contain up to 30 carbonatoms. Suitable non-aromatic cyclic group containing monomersadvantageously have at least one polymerizable olefinic group that iseither pendant on the cyclic structure or is part of the cyclicstructure. The cyclic structure can also be further substituted by oneor more hydrocarbyl groups such as, but not limited to, C₁ to C₁₀ alkylgroups. Advantageous non-aromatic cyclic group containing comonomersinclude vinylcyclohexane, vinylcyclohexene, vinylnorbornene, ethylidenenorbornene, cyclopentadiene, cyclopentene, cyclohexene, cyclobutene,vinyladamantad the like.

In one or more embodiments, diolefin comonomer(s) can be used.Advantageous diolefin comonomers include any hydrocarbon structure,advantageously C₄ to C₃₀, having at least two unsaturated bonds, whereinat least two of the unsaturated bonds are readily incorporated into apolymer by either a stereospecific or a non-stereospecific catalyst(s).It is further advantageous that the diolefin monomers be selected fromalpha-omega diene comonomers (i.e. di-vinyl monomers). Moreadvantageously, the diolefin comonomers are linear di-vinyl monomers,most advantageously those containing from 4 to 30 carbon atoms. Examplesof advantageous dienes include butadiene, pentadiene, hexadiene,heptadiene, octadiene, nonadiene, decadiene, undecadiene, dodecadiene,tridecadiene, tetradecadiene, pentadecadiene, hexadecadiene,heptadecadiene, octadecadiene, nonadecadiene, icosadiene,heneicosadiene, docosadiene, tricosadiene, tetracosadiene,pentacosadiene, hexacosadiene, heptacosadiene, octacosadiene,nonacosadiene, triacontadiene, particularly advantageous dienes include1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene,1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene,1,13-tetradecadiene, and low molecular weight polybutadienes(weight-averaged molecular weight, Mw, less than 1000 g/mol).Advantageous cyclic dienes include cyclopentadiene, vinylnorbornene,norbornadiene, ethylidene norbornene, divinylbenzene, dicyclopentadieneor higher ring containing diolefins with or without substituents atvarious ring positions.

Novel/Differentiated EP Copolymer Blend Component Composition:

In an advantageous embodiment, the process described can be used toproduce novel and differentiated random ethylene-propylene copolymerblend component with an ethylene content ranging from 10 to 20 wt %.Advantageous polymers produced herein also include terpolymers ofethylene, propylene and one or more of the optional comonomerspreviously described. In another embodiment the polymer is a copolymercomprising propylene and ethylene, and the copolymer comprises less thanor equal to 20 wt % ethylene, less than or equal to 18 wt % ethylene,less than or equal to 16 wt % ethylene, or less than or equal to 14 wt %ethylene, or less than or equal to 12 wt % ethylene. In anotherembodiment, the polymer is an ethylene-propylene random terpolymercomprising propylene and ethylene and one or more of any of thecomonomers listed above.

In another embodiment, the ethylene-propylene copolymer blend componentproduced herein is a terpolymer of propylene, ethylene and one or moreC₂ or C₄ to C₂₀ linear, branched or cyclic monomers, advantageously oneor more C₂ or C₄ to C₁₂ linear, branched or cyclic alpha-olefins.Advantageously, the terpolymer produced herein is a terpolymer ofpropylene, ethylene and one or more of butene, pentene, hexene, heptene,octene, nonene, decene, undecene, dodecene,4-methyl-pentene-1,3-methyl-pentene-1, and 3,5,5-trimethyl-hexene-1.

In another advantageous embodiment, the ethylene-propylene copolymerblend component produced herein can be a terpolymer of ethylene,propylene and one or more linear or branched C₄ to C₃₀ prochiralalpha-olefin or C₅ to C₃₀ ring-containing olefins or combinationsthereof capable of being polymerized by either stereospecific andnon-stereospecific catalysts. Prochiral, as used herein, refers tomonomers that favor the formation of isotactic or syndiotactic polymerwhen polymerized using stereospecific catalysts.

In another embodiment, the ethylene-propylene copolymer blend componentcomprises propylene present at from 70 to 90 wt %, or 80 to 90 wt %, or82 to 90 wt %, and ethylene present at from 10 to 20 wt %, or 10 to 18wt %, or 10 to 16 wt %, and an optional comonomer present at from 0.5 to10 wt %, or from 0.5 to 8 wt %, or 1 to 5 wt %.

Conventional Isotactic Polypropylene Blend Component

The isotactic polypropylene blend components may be conventional incomposition, and made by gas phase, slurry, or solution type process andcommercially available from virtually all large petrochemicalcorporations, like ExxonMobil Chemical Co., Basell, Novatec, Formosa,etc., under various trade names, such as Achieve, Metocene, etc. For acomprehensive description of conventional isotactic polypropylenes,refer to the PROPYLENE HANDBOOK, E. P. Moore, Ed., Hanser, New York,1996. Off-line-produced conventional polypropylenes may be in-lineblended after dissolving them in proper solvents, such as C₆ to C₁₀hydrocarbons. However, due to the difficulty of such processes, in-lineproduction of polypropylenes in homogeneous polymerization processes,such as solution or homogeneous supercritical polymerization isadvantageous. Of these homogeneous processes, conventional solutionprocesses operating with low propylene concentration (typically lessthan 2.0 mol/L or less than 1.5 mol/L, or less than 1.0 mol/L, or lessthan 0.5 mol/L in the reactor effluent) tend to make lower molecularweight conventional polypropylenes (see comparative examples disclosedherein). These conventional isotactic polypropylene components may bein-line blended with novel differentiated or novel EP copolymer blendcomponents using the in-line blending processes disclosed herein to formnovel iPP-EP copolymer blends.

Novel/Differentiated Isotactic PP Blend Component

Described below is the composition, process for making, and propertiesof novel differentiated isotactic polypropylene blend components for usein the in-line produced iPP and EP copolymer blends disclosed herein.

The novel isotactic polypropylene (iPP) blend component advantageouslyhas a weight-average molecular weight (Mw) of 35,000 g/mol or more. Inone or more embodiment, the Mw can be 50,000 g/mol or more; 75,000 g/molor more; 100,000 g/mol or more; 125,000 g/mol or more; 150,000 g/mol ormore; 200,000 g/mol or more; or 500,000 g/mol or more. The propylenehomopolymer advantageously has an Mw ranging from about 35,000 to1,000,000; alternately from 50,000 to 1,000,000; alternately from 75,000to 750,000; alternately from 100,000 to 400,000 g/mol. Weight averagemolecular weights (Mw) are determined using Gel-PermeationChromatography (GPC), as described in more detail below.

The propylene homopolymer advantageously has a peak melting point, alsoreferred as peak melting temperature, or melting peak temperature (Tmp)of 149° C. or more, advantageously 150° C. or more, advantageously 151°C. or more, or 152° C. or more, or 153° C. or more, or 154° C. or more,or 155° C. or more. In one or more embodiments, the peak meltingtemperature can range from about 149° C. to about 170° C., or from 150°C. to about 170° C., or from 151° C. to about 165° C., or from 152° C.to 165° C. Peak melting temperature (Tmp) is determined usingDifferential Scanning Calorimetry (DSC), as described in more detailbelow.

In one or more embodiments, the homopolymer described herein has a peakmelting temperature minus peak crystallization temperature (Tmp−Tcp) ofless than or equal to (0.907 times Tmp) minus 99.64° C. (or expressed bythe formula of Tmp−Tcp≦(0.907×Tmp)−99.64° C.), as measured on thehomopolymer having 0 wt % nucleating agent, advantageouslyTmp−Tcp≦(0.907×Tmp)−100.14° C., more advantageouslyTmp−Tcp≦(0.907×Tmp)−100.64° C. In the current disclosure, the differencebetween the melting and crystallization peak temperatures (Tmp−Tcp) asmeasured by DSC will be also referred to as supercooling temperature andwill be expressed in ° C.

In one or more embodiments, the propylene homopolymer advantageously hasmore than 15 and less than 100 regio defects (defined as the sum of2,1-erythro, 2,1-threo insertion, and 3,1-isomerization) per 10,000propylene units and mmmm pentad fraction of at least 0.85, alternatelymore than 17 and less than 100 defects per 10,000 propylene units,alternately more than 20 or 30 or 40, but less than 95 regio defects per10,000 propylene units. The regio defects are determined using ¹³C NMRspectroscopy as described below.

The propylene homopolymer advantageously has a heat of fusion (ΔHf) of80 J/g or more, or 90 J/g or more, or 100 J/g or more, or 110 J/g ormore, or 120 J/g or more. Heat of fusion (Hf, or ΔHf) is determined byusing Differential Scanning Calorimetry (DSC), as described in moredetail below.

The disclosed propylene homopolymers have little or extremely lowinorganic residues typically originating from the catalyst systems(i.e., from the catalyst precursors, activators, and optional supports)and the optional scavengers, such as, for example, alkyl aluminumcompounds, or methyl aluminoxane (MAO), etc. In some embodiments, thepolymer product has less than 1 wt % silica, or less than 0.1 wt %silica, or less than 100 wt ppm silica, or less than 10 wt ppm silica.In other embodiments, the polymer product contains less than less than100 wt ppm Group-4 transition metal, or less than 10 wt ppm Group-4metal. In a preferred embodiment, the disclosed homopolymers have acombined Group-4 transition metal (e.g., Ti, Zr, or Hf) and aluminumcontent of 100 wt ppm or less, or 50 wt ppm or less, or 10 weight ppm orless.

The disclosed propylene homopolymers have narrow molecular weightdistribution (MWD) expressed as the ratio of the number and weightaverage molecular weights (Mw/Mn, measured by GPC with DRI detector) of1.2 to 5, or 1.5 to 4, or 1.8 to 3.5 or 1.8 to 3, or 1.8 to 2.5.Advantageously, the Mw/Mn is greater than 1 and less than or equal to 5.

The propylene homopolymer advantageously has a melt viscosity of lessthan 10,000 centipoises (cps) at 180° C. as measured on a Brookfieldviscometer, advantageously between 1000 to 3000 cps for some embodiments(such as packaging and adhesives) and advantageously between 5,000 and10,000 for other applications.

The disclosed propylene homopolymers have a melt flow rate (MFR, ASTMD1238 at 230° C./2.16 kg) of 20,000 g/min or less, or 15,000 g/10 min orless, or 0.1 to 20,000, or 0.1, to 15,000, or 0.1 to 10,000, or 0.1 to5,000, or 1 to 20,000, or 1 to 10,000, or 1 to 5,000, or 10 to 5,000, or1 to 500, or 10 to 500 g/10 min.

The propylene homopolymer described herein advantageously has acrystallization half time (Tc-half), as measured by differentialscanning calorimetry (DSC), in the absence of any nucleating agents(e.g. 0 wt %), at 126° C. of 12.0 minutes or less, preferably 12.0 to3.9 minutes, preferably 11.5-to 3.4 minutes, preferably 11.0 to 2.9minutes, more preferably 10.5 to 2.4 minutes.

Novel/Differentiated iPP Homogeneous Polymerization Process Details:

In one or more embodiments, the process to produce polypropylenedescribed herein includes contacting propylene, in a polymerizationsystem, with one or more catalyst systems, at a temperature above 90° C.and at a pressure above 12 MPa. The polymerization advantageously takesplace in a homogeneous polymerization system within a continuouspolymerization reactor. In one or more embodiments, about 40 wt % ormore propylene monomer, based on total weight of propylene monomer andoptional inert solvent and/or inert diluent, and up to about 60 wt %inert solvent, based on total weight of propylene monomer and optionalinert solvent and inert diluent, is fed into a polymerization reactor.Advantageously, about 28 wt % or more propylene monomer, based on totalweight of the polymerization system, is present in the reactor effluentat steady state conditions. In one or more embodiments above orelsewhere herein, the monomer feed to the process can include one ormore diluents. Scavengers and co-catalysts can also be included in thereactor feed.

In one or more embodiments, the monomer feed can contain 40 wt % ormore, 45 wt % or more, or 50 wt % or more, 55 wt % or more, or 60 wt %or more, or 65 wt % or more, or 70 wt % or more, or 75 wt % or more, or80 wt % or more, or 85 wt % or more, or 90 wt % or more propylene, basedon total weight of propylene and optional inert solvents and/or inertdiluents entering the reactor. In one or more embodiments, the monomerfeed can contain monomer ranging from about 40 wt % to about 85 wt %,based on total weight of propylene and optional inert solvents and/orinert diluents entering the reactor. In one or more embodiments, themonomer feed can contain monomer ranging from about 40 wt % to about 75wt %, based on total weight of monomer and optional inert solventsand/or inert diluents entering the reactor. In one or more embodiments,the monomer feed can contain propylene ranging from about 40 wt % toabout 65 wt %, based on total weight of monomer and optional inertsolvents and/or inert diluents entering the reactor.

In one or more embodiments, the polymerization system contains up to 60wt % inert solvent. In one or more embodiments, the polymerizationsystem contains more than 35 wt % and less than 60 wt % inert solvent ormore than 35 and less than 65 wt % inert solvent, or more than 35 andless than 70 wt % inert solvent. In one or more embodiments, thepolymerization system contains of from 40 wt % to 60 wt % inert solvent.In one or more embodiments, the inert solvent content of thepolymerization system can range from a low of about 40 wt %, 45 wt %, or50 wt %, or 60 wt %, or 65 wt % to a high of about 65 wt %. The inertsolvent typically comprises hydrocarbons containing from 4 to 100 carbonatoms, advantageously from 4 to 8 carbon atoms. In certain embodiments,the inert solvent is or includes hexane isomers.

Not wishing to be bound by theory, it is believed that the highconcentration of propylene increases the molecular weight of the productor allows higher-temperature operations while making the same polymergrade, thus enabling the production of polymer grades otherwiseinaccessible, or reduces the cost of monomer recycle and reactorcooling. Increased concentration of solvents, on the other hand,depresses the cloud point of the polymerization system allowinghomogeneous reactor operations at lower pressures, which in turn reducesthe investment and compression costs. Therefore, there is an optimummonomer/solvent concentration for achieving the lowest production costof a given polypropylene grade at a given location and at a given time.This optimum depends on many factors, among other things, on the cost ofreactor construction, the cost of energy and cooling, etc. The optimumsolvent composition and concentration for any given product slate andlocation can be determined by standard methods known in the art ofchemical engineering.

In one or more embodiments, the density of the polymerization system isabout 0.3 g/mL or more, or about 0.4 g/mL or more, or about 0.5 g/mL ormore, or about 0.6 g/mL or more.

In one or more embodiments, the steady state polymer yield (i.e.conversion of propylene monomer to polymer product in a single passthrough the reactor is at least 5 wt % of the propylene monomer fed tothe reactor. In one or more embodiments, the conversion of propylenemonomer to polymer product in a single pass through the reactor is atleast 10%. In one or more embodiments, the conversion of propylenemonomer to polymer product in a single pass through the reactor is atleast 20%, or at least 30%, or at least 40% but less than 90%, or lessthan 80%, or less than 70% in a single pass through the reactor.

In one or more embodiments, the polymerization conditions are sufficientto maintain the polymerization system in a single, homogeneous fluidstate. For example, the minimum reaction temperature and pressure can beselected so that the polymer produced, and the polymerization systemthat solvates it, remain single phase, i.e. above the polymerizationsystem's cloud point and above its solid-fluid phase transitiontemperature and pressure with that polymer. Also, lower temperaturesgenerally favor higher crystallinity and higher molecular weight, whichare often key product attributes to meet. Furthermore, for homogeneouspolymerization processes, the lower limits of reaction temperature canalso be determined by the solid-fluid phase transition temperature.Reactors operated below the solid-fluid phase transition temperature ofthe reaction mixture can lead to operation problems due to fouling. Forthe production of highly crystalline polypropylenes (melting peaktemperatures>150° C.) in homogeneous polymerization processes, theminimum operating temperature is about 93 to 100° C. The application ofcertain inert solvents can further reduce the minimum operationtemperature of the fouling-free operation regime, although thesubstantial presence of inert solvents can reduce polymerization rate,product molecular weight, and can depress the melting peak temperature.The upper limit for temperature can be determined by the productproperties that are strongly influenced by the reaction temperature.Since often polymers with higher molecular weights and/or higher meltingtemperatures are desired, high polymerization temperatures (>200° C.)are generally not advantageous. Increased temperatures can also degrademany known catalytic systems, providing another reason for avoidingexcessive polymerization temperatures. From this perspective,temperatures below 250° C. are useful. Obviously, the optimum reactorconditions are influenced by the product specifications and reactoroperation issues as outlined above. Advantageously, the polymerizationtemperatures for the production of the disclosed polypropylenes aretypically between 90 and 200° C., or between 90 and 180° C., or between90 and 150° C., or between 93 and 150° C., or between 93 and 140° C., orbetween 95 and 140° C.

In one or more embodiments, the polymerization conditions are sufficientto dissolve the polymer product essentially in the monomer, which ispresent in the liquid state. These embodiments fall into the category of“bulk solution polymerization”. In other embodiments, the polymerizationconditions are sufficient to dissolve the polymer product essentially inthe monomer, which is present in the supercritical state. Theseembodiments fall into the category of “bulk supercriticalpolymerization”. The polymerization system can form one single fluidphase or two fluid phases.

In one or more embodiments, the reaction temperature and pressure can beselected so that the polymerization system remains at a pressure belowthe polymer's cloud point in the particular polymerization system,resulting in a two-phase polymerization system forming a polymer-richphase and a polymer-lean phase. Some embodiments that are below thepolymer's cloud point nonetheless operate above the polymer'scrystallization temperature. The terms “two-phase system” or “two-phasepolymerization system” refer to a polymerization system having two and,advantageously, only two phases. In certain embodiments, the two phasesare referenced as a “first phase” and a “second phase.” In certainembodiments, the first phase is or includes a “monomer phase,” whichincludes monomer(s) and can also include diluent and some or all theproduct of polymerization. In certain embodiments, the second phase isor includes a solid phase, which can include products of polymerization,e.g., macromers and polymer product, but not monomers, e.g., propylene.While operations with such two-phase polymerization system is feasible,they may cause operability issues, particularly downstream of thereactor, thus reactor operations above the cloud point, i.e., in asingle-phase polymerization system are advantageous over the two-phasepolymerization system.

In the disclosed processes for making highly crystalline polypropyleneswith the above-described melting and supercooling properties and defectstructure, the reaction pressure can be no lower than the solid-fluidphase transition pressure of the polymer-containing dense fluidpolymerization system at the reactor temperature. In another embodiment,the pressure is no lower than 10 MPa below the cloud point of the fluidreaction medium at the reactor temperature. In another embodiment, thepressure is between 12 and 1500 MPa, or between 12 and 207 MPa, orbetween 12 and 138 MPa, or between 69 MPa, or between 12 and 55 MPa, orbetween 34.5 and 138 MPa, or between 34.5 and 83 MPa, between 12 and13.8 MPa. In another embodiment, the pressure is above 12, 20.7, or 34.5MPa. In another embodiment, the pressure is below 1500, 500, 207, 138,83, 69, 55, or 13.8 MPa.

Novel/Differentiated Isotactic Polypropylene Polymerization Reactors:

Polymerizations for the one or more iPP parallel reactor trains may becarried out either in a single reactor, or in two or more reactorsconfigured in series or parallel. The catalyst system can be deliveredas a solution or slurry, either separately to the reactor, activatedin-line just prior to the reactor, or preactivated and pumped as anactivated solution or slurry to the reactor. Since heterogeneous (solid)catalysts are often difficult to handle in disclosed homogeneouspolymerization processes (they tend to cause plugging and increasedwear), advantageous catalyst systems are soluble in the polymerizationsystem. In one embodiment, two solutions, one comprising the one or morecatalyst precursor compounds and another comprising the activator, areblended in-line either in or prior to feeding them to the reactor. Inother embodiments, the one or more catalyst precursor compounds arepremixed with the one or more activators in solution, and a solution ofthe already activated catalyst is fed to the reactor.

In any operation mode, the catalyst system may comprise one, or morethan one catalyst precursor and one or more activator. In both single-and multi-reactor operations, the one or more catalyst systems may beintroduced at one point or at multiple points to the one or morepolymerization reactors. Various feed configurations can be useddepending on such factors as the desired product properties, such as,for example, molecular weight distribution, or catalyst stability. Suchfeed configurations are well known in the art of chemical engineeringand can be readily optimized for the desired production scale andproduct properties using known engineering techniques.

In one or more embodiments, polymerization can occur in high-pressurereactors where, advantageously, the reactor is substantially unreactivewith the polymerization reaction components and is able to withstand thehigh pressures and temperatures that occur during the polymerizationreaction. Such reactors are known as high-pressure reactors for purposesof this disclosure. Withstanding these high (typically higher than 13.8or higher than 34.5, or higher than 69.0 MPa, or higher than 137.9 MPa)pressures and temperatures will allow the reactor to maintain thepolymerization system in its homogeneous condition. Suitable reactionvessels include those known in the art to maintain high-pressurepolymerization reactions. Suitable reactors are selected from autoclave,pump-around loop, autoclave, tubular, and combinations thereof.

Autoclave reactors may be operated in either a batch or continuous mode,although the continuous mode is advantageous. Tubular reactors alwaysoperate in continuous mode. Typically, autoclave reactors havelength-to-diameter ratios of 1:1 to 20:1 and are fitted with ahigh-speed (up to 2000 RPM) multiblade stirrer and baffles arranged foroptimal mixing. Commercial autoclave pressures are typically greaterthan 5 MPa with a maximum of typically less than 260 MPa. The maximumpressure of commercial autoclaves, however, may become higher withadvances in mechanical and material science technologies.

When the autoclave has a low length-to-diameter ratio (such as less thanfour), the feed streams may be injected at one position along the lengthof the reactor. Reactors with large diameters may have multipleinjection ports at nearly the same or different positions along thelength of the reactor. When they are positioned at the same length ofthe reactor, the injection ports are radially distributed to allow forfaster intermixing of the feed components with the reactor content. Inthe case of stirred tank reactors, the separate introduction of thecatalyst and monomer may be advantageous in preventing the possibleformation of hot spots in the unstirred feed zone between the mixingpoint and the stirred zone of the reactor. Injections at two or morepositions along the length of the reactor is also possible and may beadvantageous. In one exemplary embodiment, in reactors where thelength-to-diameter ratio is from 4 to 20, the reactor may contain up tosix different injection positions along the reactor length with multipleports at some or each of the lengths.

Additionally, in the larger autoclaves, one or more lateral mixingdevices may support the high-speed stirrer. These mixing devices canalso divide the autoclave into two or more zones. Mixing blades on thestirrer may differ from zone to zone to allow for a different degree ofplug flow and back mixing, largely independently, in the separate zones.Two or more autoclaves with one or more zones may connect in a seriesreactor cascade to increase residence time or to tailor polymerstructure in a reactor train producing a polymer blending component. Aspreviously described, a series reactor cascade or configuration consistsof two or more reactors connected in series, in which the effluent of atleast one upstream reactor is fed to the next reactor downstream in thecascade. Besides the effluent of the upstream reactor(s), the feed ofany reactor in the series reactor cascade of a reactor train can beaugmented with any combination of additional monomer, catalyst, orsolvent fresh or recycled feed streams. Therefore, it should beunderstood that the polymer blending component leaving a reactor trainof the process disclosed herein may itself be a blend of the samepolymer with increased molecular weight and/or compositional dispersionor even a blend of homo- and copolymers.

Tubular reactors may also be used in the processes disclosed herein andmore particularly tubular reactors capable of operating up to about 350MPa. Tubular reactors are fitted with external cooling and one or moreinjection points along the (tubular) reaction zone. As in autoclaves,these injection points serve as entry points for monomers (such aspropylene), one or more comonomer, catalyst, or mixtures of these. Intubular reactors, external cooling often allows for increased monomerconversion relative to an autoclave, where the low surface-to-volumeratio hinders any significant heat removal. Tubular reactors have aspecial outlet valve that can send a pressure shockwave backward alongthe tube. The shockwave helps dislodge any polymer residue that hasformed on reactor walls during operation. Alternatively, tubularreactors may be fabricated with smooth, unpolished internal surfaces toaddress wall deposits. Tubular reactors generally may operate atpressures of up to 360 MPa, may have lengths of 100-2000 meters or100-4000 meters, and may have internal diameters of less than 12.5 cm.Typically, tubular reactors have length-to-diameter ratios of 10:1 to50,000:1 and include up to 10 different injection positions along itslength.

Reactor trains that pair autoclaves with tubular reactors are alsocontemplated within the scope of the polymerization processes disclosedherein for making highly crystalline polypropylenes. In this reactorsystem, the autoclave typically precedes the tubular reactor or the twotypes of reactors form separate trains of a parallel reactorconfiguration. Such reactor systems may have injection of additionalcatalyst and/or feed components at several points in the autoclave, andmore particularly along the tube length. In both autoclaves and tubularreactors, at injection, feeds are typically cooled to near ambienttemperature or below to provide maximum cooling and thus maximum polymerproduction within the limits of maximum operating temperature. Inautoclave operation, a preheater may operate at startup, but not afterthe reaction reaches steady state if the first mixing zone has someback-mixing characteristics. In tubular reactors, the first section ofdouble-jacketed tubing may be heated (especially at start ups) ratherthan cooled and may operate continuously. A well-designed tubularreactor is characterized by plug flow wherein plug flow refers to a flowpattern with minimal radial flow rate differences. In both multizoneautoclaves and tubular reactors, catalyst can not only be injected atthe inlet, but also optionally at one or more points along the reactor.The catalyst feeds injected at the inlet and other injection points canbe the same or different in terms of content, density, andconcentration. Catalyst feed selection allows polymer design tailoringwithin a given reactor or reactor train and/or maintaining the desiredproductivity profile along the reactor length.

At the reactor outlet valve, the pressure drops to begin the separationof polymer and unreacted monomer, co-monomers, solvents and inerts, suchas for example ethane, propane, hexane, and toluene. More particularly,at the reactor outlet valve, the pressure drops to levels below thatwhich critical phase separation allowing for a polymer-rich phase and apolymer-lean phase in the downstream separation vessel. Typically,conditions remain above the polymer product's crystallizationtemperature. The autoclave or tubular reactor effluent may bedepressurized on entering the downstream high-pressure separator (HPS).The temperature in the separation vessel is maintained above thesolid-fluid phase separation temperature.

In addition to autoclave reactors, tubular reactors, or a combination ofthese reactors, loop-type reactors may be utilized in the polymerizationprocesses disclosed herein. In this reactor type, monomer enters andpolymer exits continuously at different points along the loop, while anin-line pump continuously circulates the contents (reaction liquid). Thefeed/product takeoff rates control the total average residence time. Acooling jacket removes reaction heat from the loop. Typically feed inlettemperatures are near to or below ambient temperatures to providecooling to the exothermic reaction in the reactor operating above thecrystallization temperature of the polymer product. The loop reactor mayhave a diameter of 41 to 61 cm and a length of 100 to 200 meters and mayoperate at pressures of 25 to 30 MPa. In addition, an in-line pump maycontinuously circulate the polymerization system through the loopreactor.

The polymerization processes of polymerization processes disclosedherein may have residence times in the reactors as short as 0.5 secondsand as long as several hours, alternatively from 1 sec to 120 min,alternatively from 1 second to 60 minutes, alternatively from 5 secondsto 30 minutes, alternatively from 30 seconds to 30 minutes,alternatively from 1 minute to 60 minutes, and alternatively from 1minute to 30 minutes. More particularly, the residence time may beselected from 10, or 30, or 45, or 50, seconds, or 1, or 5, or 10, or15, or 20, or 25, or 30 or 60 or 120 minutes. Maximum residence timesmay be selected from 1, or 5, or 10, or 15, or 30, or 45, or 60, or 120minutes.

The monomer-to-polymer conversion rate (also referred to as theconversion rate) is calculated by dividing the total quantity of polymerthat is collected during the reaction time by the amount of monomeradded to the reaction. Lower conversions may be advantageous to limitviscosity although increase the cost of monomer recycle. The optimumtotal monomer conversion thus will depend on reactor design, productslate, process configuration, etc., and can be determined by standardengineering techniques. Total monomer conversion during a single passthrough any individual reactor of the fluid phase in-line process forblending disclosed herein may be up to 90%, or below 80%, or below 60%or 3 to 80%, or 5 to 80%, or 10 to 80%, or 15 to 80%, or 20 to 80%, or25 to 60%, or 3 to 60%, or 5 to 60%, or 10 to 60%, or 15 to 60%, or 20to 60%, or 10 to 50%, or 5 to 40%, or 10 to 40%, or 40 to 50%, or 15 to40%, or 20 to 40%, or 30 to 40% or greater than 5%, or greater than 10%.

Advantageously, catalyst productivities range from 100 to 500,000 kgPP/(kg catalyst hr). This high level of catalyst productivity incombination of using unsupported catalysts, can result in low residualinorganic residues in the polymer product. In some embodiments, thepolymer product has less than 1 weight % silica, or less than 0.1 wt %silica, or less than 100 wt ppm silica, or less than 10 wt ppm silica.In other embodiments, the polymer product contains less than less than100 wt ppm Group-4 transition metal, or less than 10 wt ppm Group-4metal. In a preferred embodiment, the disclosed homopolymers have acombined Group-4 transition metal (e.g., Ti, Zr, or Hf) and aluminumcontent of 100 wt ppm or less, or 50 wt ppm or less, or 10 weight ppm orless.

Novel/Differentiated Isotactic Polypropylene Reaction Conditions:

The reaction temperature can be above the solid-fluid phase transitiontemperature of the polymer-containing fluid reaction medium at thereactor pressure, advantageously at least 5° C. above the solid-fluidphase transition temperature of the polymer-containing fluid reactionmedium at the reactor pressure. More advantageously, at least 10° C.above the solid-fluid phase transformation point of thepolymer-containing fluid reaction medium at the reactor pressure. Inanother embodiment, the temperature is above the cloud point of thesingle-phase fluid reaction medium at the reactor pressure. Moreadvantageously 2° C. or more above the cloud point of the fluid reactionmedium at the reactor pressure. In another embodiment, the temperatureis between 50 and 350° C., between 60 and 250° C., between 70 and 250°C., or between 80 and 250° C. In another embodiment, the temperature isabove 50, 60, 70, 80, 90, 95, 100, 110, or 120° C. In anotherembodiment, the temperature is below 350, 250, 240, 230, 220, 210, or200° C. In another embodiment, the cloud point temperature is above thesupercritical temperature of the polymerization system. In anotherembodiment, the cloud point temperature is between 50 and 350° C.,between 60 and 250° C., between 70 and 250° C., or between 80 and 250°C. In another embodiment, the cloud point temperature is above 50, 60,70, 80, 90, 95, 100, 110, or 120° C. In another embodiment, the cloudpoint temperature is below 350, 250, 240, 230, 220, 210, or 200° C.

The reaction pressure can be no lower than the crystallization phasetransition pressure of the polymer-containing fluid reaction medium atthe reactor temperature. In another embodiment, the pressure is no lowerthan 10 MPa below the cloud point of the fluid reaction medium at thereactor temperature. In another embodiment, the pressure is between 10and 500 MPa, between 10 and 300 MPa, or between 20 and 250 MPa. Inanother embodiment, the pressure is above 10, 20, or 30 MPa. In anotherembodiment, the pressure is below 1500, 500, 300, 250, or 200 MPa. Inanother embodiment, the cloud point pressure is between 10 and 500 MPa,between 10 and 300 MPa, or between 20 and 250 MPa. In anotherembodiment, the cloud point pressure is above 10, 20, or 30 MPa. Inanother embodiment, the cloud point pressure is below 1500, 500, 300,250, or 200 MPa.

Isotactic PP-EP Copolymer Blend Formulations

Many different types of iPP and EP copolymer blends may be made by thefluid phase in-line blending process disclosed herein. A major fractionof a blend is defined as 50% or more by weight of the blend. A minorfraction of a blend is defined as less than 50% by weight of the blend.

In some forms the iPP and EP copolymer blends produced by the processesdisclosed herein include a major fraction of the EP copolymer component,wherein the EP copolymer component may be from 50 to 99 wt %, based uponthe weight of the polymers in the blend, or 55 to 98 wt %, or 60 to 95wt %, or 65 to 90 wt %, or 70 to 85 wt %, or 75 to 80 wt %, with the iPPand any polymer additives constituting the remainder of the blend. Hencethe iPP blend component will generally constitute a minor fraction ofthe blend, wherein the iPP component may be from 1 to 50 wt %, basedupon the weight of the polymers in the blend, or 2 to 45 wt %, or 5 to40 wt %, or 10 to 35 wt %, or 15 to 30 wt %, or 20 to 25 wt %.

In one embodiment of the novel iPP-EP copolymer blends disclosed herein,the blend includes a novel or differentiated EP copolymer componentdescribed above in combination with a conventional isotacticpolypropylene component. In particular, the blend includes between 50and 99 wt % of an ethylene-propylene copolymer component includingbetween 10 wt % and 20 wt % randomly distributed ethylene with a meltflow rate of between 0.5 and 20,000 g/10 min, wherein the copolymer ispolymerized by a bulk homogeneous polymerization process, and whereinthe total regio defects in the continuous propylene segments of thecopolymer is between 40 and 150% greater than a copolymer of equivalentmelt flow rate and wt % ethylene polymerized by a solutionpolymerization process, and between 1 and 50 wt % of isotacticpolypropylene with a melt flow rate of between 0.5 and 20,000 g/10 min.In another form of this embodiment, the total regio defects in thecontinuous propylene segments of the EP copolymer may be between 40 and100% greater than a copolymer of equivalent melt flow rate and wt %ethylene polymerized by a solution polymerization process. In yetanother form of this embodiment, the melt flow rate of the EP copolymermay be between 0.5 and 5,000 g/10 min. In still yet another form of thisembodiment, the total regio defects in the continuous propylene segmentsof the EP copolymer may be greater than 0.50 mol %, or greater than 0.70mol %. In still yet another form of this embodiment, the peak meltingtemperature of the EP copolymer may be between 35° and 80° C. The EPcopolymer component may also optionally comprise between 0.5 wt % and 50wt % of randomly distributed butene-1, pentene-1, hexene-1, octene-1,decene-1, or combinations thereof.

In another embodiment of the novel iPP-EP copolymer blends disclosedherein, the blend includes a novel or differentiated isotacticpolypropylene in combination with a conventional ethylene-propylenecopolymer. In particular, the blend includes between 1 and 50 wt % ofisotactic polypropylene with a melt flow rate of between 0.5 and 20,000g/10 min and a melting peak temperature of 145° C. or higher, andwherein the difference between the DSC peak melting and the peakcrystallization temperatures is less than or equal to 0.5333 times themelting peak temperature minus 41.333° C., and between 50 and 99 wt % ofethylene-propylene copolymer including between 10 wt % and 20 wt %randomly distributed ethylene with a melt flow rate of between 0.5 and20,000 g/10 min. In another form of this embodiment, the melt flow rateof the isotactic polypropylene is between 10 and 100 g/10 min. In yetanother form of this embodiment, the total regio defects in thecontinuous propylene segments of the isotactic polypropylene is greaterthan 15 and less than 100 regio defects per 10,000 propylene units inthe polymer chain, or greater than 30 and less than 100 regio defectsper 10,000 propylene units in the polymer chain. In still yet anotherform or this embodiment, the DSC peak crystallization temperature of theisotactic polypropylene is greater than 109° C. In still yet anotherform or this embodiment, the isotactic polypropylene has a DSC peakmelting temperature of 150° C. or higher, and a weight-averagedmolecular weight of 35 kg/mol or higher, or 80 kg/mol or higher.

In yet another embodiment of the novel iPP-EP copolymer blends disclosedherein, the blend includes novel/differentiated isotactic polypropylenecomponents in combination with novel/differentiated ethylene-propylenecopolymer components. In particular, the blend includes between 1 and 50wt % of isotactic polypropylene with a melt flow rate of between 0.5 and20,000 g/10 min and a melting peak temperature of 145° C. or higher, andwherein the difference between the DSC peak melting and the peakcrystallization temperatures is less than or equal to 0.5333 times themelting peak temperature minus 41.333° C., and between 50 and 99 wt % ofethylene-propylene copolymer including between 10 wt % and 20 wt %randomly distributed ethylene with a melt flow rate of between 0.5 and20,000 g/10 min, wherein the copolymer is polymerized by a bulkhomogeneous polymerization process, and wherein the total regio defectsin the continuous propylene segments of the copolymer is between 40 and150% greater than a copolymer of equivalent melt flow rate and wt %ethylene polymerized by a solution polymerization process. In anotherform of this embodiment, the melt flow rate of the isotacticpolypropylene may be between 10 and 5,000 g/10 min, or 10 and 150 g/10min, or 10 and 100 g/10 min. In another form of this embodiment, thetotal regio defects in the continuous propylene segments of theisotactic polypropylene may be greater than 15 and less than 100 regiodefects per 10,000 propylene units in the polymer chain, or greater than30 and less than 100 regio defects per 10,000 propylene units in thepolymer chain. In another form of this embodiment, the DSC peakcrystallization temperature of the isotactic polypropylene may begreater than 109° C. In another form of this embodiment, the isotacticpolypropylene may have a DSC peak melting temperature of 150° C. orhigher, and a weight-averaged molecular weight of 35 kg/mol or higher,or 80 kg/mol or higher. In another form of this embodiment, the totalregio defects in the continuous propylene segments of the EP copolymermay best between 40 and 100% greater than a copolymer of equivalent meltflow rate and wt % ethylene polymerized by a solution polymerizationprocess. In yet another form of this embodiment, the melt flow rate ofthe EP copolymer may be between 0.5 and 5,000 g/10 min. In still yetanother form of this embodiment, the total regio defects in thecontinuous propylene segments of the EP copolymer may be greater than0.50 mol %, or greater than 0.70 mol %. In still yet another form ofthis embodiment, the peak melting temperature of the EP copolymer may bebetween 35° and 80° C. The EP copolymer component may also optionallycomprise between 0.5 wt % and 50 wt % of randomly distributed butene-1,pentene-1, hexene-1, octene-1, decene-1, or combinations thereof.

In another form, in-line iPP-EP copolymer blends are produced frompropylene-based polymers made at homogeneous polymerization conditions,particularly at bulk homogeneous polymerization conditions, such as bulkhomogeneous supercritical or bulk solution polymerization, and comprisethe following:

-   (a) 10 to 20 wt % of isotactic polypropylene with 0.8 to 20,000 g/10    min MFR and melting peak temperatures of 80 to 165° C. plus 80 to 90    wt % crystallizable ethylene-propylene copolymer comprising 10 to 16    wt % ethylene content and 0.8 to 100 g/10 min MFR; or-   (b) 15 to 50 wt % of isotactic polypropylene with 0.8 to 20,000 g/10    min MFR and melting peak temperatures of 80 to 165 ° C. plus 50 to    85 wt % propylene copolymer of isotactic polypropylene crystallinity    comprising 1 to 20 wt % ethylene and 0.8 to 100 g/10 min MFR; or-   (c) 10 to 30 wt % of isotactic polypropylene with 0.8 to 20,000 g/10    min MFR and melting peak temperatures of 80 to 165° C. plus 90 to 70    wt % low-crystallinity (0 to 30 J/g) EP copolymer with MFR of 0.8 to    500 g/10 min.

The novel iPP and EP copolymer blends produced by the fluid phasein-line blending process disclosed herein may be used to provide bi- ormulti-modality to the distributions of the molecular characteristics ofresins encompassed herein. The result of such bimodality is to producean improved suite of properties in the blend as compared to any of thepolymer components alone. Processing ease and melt strength may beimproved by such blending as well as the balance betweenstiffness-toughness, heat resistance, tolerance of exposure to highenergy radiation and other properties of the resins.

One non-limiting example of an iPP and EP copolymer blend made by thefluid phase in-line blending process disclosed herein includes a majorfraction of a highly crystalline moderate molecular weight iPP and aminor fraction of a very high molecular weight, elastomeric EP copolymerwith low or no inherent crystallinity. Another non-limiting example of auseful polymer blend made by the fluid phase in-line blending processdisclosed herein includes a major fraction of a soft, tough, low meltingEP copolymer with a minor fraction of a highly crystalline, high meltingiPP. Still another non-limiting example of a useful iPP and EP copolymerblend made by the fluid phase in-line blending process disclosed hereinincludes a major fraction of a highly crystalline iPP with a minorfraction of a low or non-crystalline EP copolymer where the low ornon-crystalline polymer is non-elastomeric.

Isotactic PP-EP Copolymer Blend Applications

The novel iPP and EP copolymer blends disclosed herein provide forimproved properties, and hence may be used in any known thermoplastic orelastomer application. Non-limiting examples include uses in moldedparts, films, tapes, sheets, tubing, hose, sheeting, wire and cablecoating, adhesives, shoe soles, bumpers, gaskets, bellows, films,fibers, elastic fibers, nonwovens, spunbonds, sealants, surgical gownsand medical devices.

One such exemplary, but non-limiting application, is in medicalapplications requiring improved resistance to sterilizing doses ofhigh-energy radiation. A polymer blend useful for this particularapplication may include from 75 to 99 wt % moderate molecular weight iPPblend component with 1 to 25 wt % of a propylene-ethylene copolymercontaining from 8 to 16 wt % ethylene. The high propylene copolymercomponent of the blend provides superior initial ductility as well asretention of ductility and tolerance of the sterilizing radiation to theblend while the homopolymer component imparts excellent strength,stiffness and resistance to deformation at elevated temperature to theblend. Polymer blends of iPP blend component and propylene-ethylenecopolymer are generally clearer or nearly as clear as the unblended iPPblend component.

Another exemplary, but non-limiting application of where the polymerblends made by the fluid phase in-line blending process disclosed hereinfind application is in various conversion processes. In particular, bycombining high and low molecular weight propylene polymers in eithersimilar or different proportion, the molecular weight distribution ofthe blend may be significantly broader than of either individualcomponent. The ratio for blending the high and low molecular weightpropylene polymers depends upon the desired final melt flow rate andmolecular weight distribution. Such broader molecular weightdistribution polymers are easier to extrusion blow mold, blow into film,thermoform, orient into film, and stretch blow mold than narrowermolecular weight distribution polymers. Optionally, one of the polymercomponents can have long chain branching introduced through addition ofa small quantity of alpha-omega-diene.

Still another exemplary, but non-limiting application of where thepolymer blends made by the fluid phase in-line blending processdisclosed herein find application is in devices and packaging materialsrequiring good impact resistance, and particularly in low temperatureenvironments. Polymer blends useful for this particular application mayinclude from 60 to 99 wt % of a stiff iPP blend component and/or arelatively stiff, low comonomer containing propylene copolymer and 1 to40 wt % of a propylene copolymer containing 5 to 20 wt % of comonomer,or comonomer-propylene elastomer (like ethylene-propylene rubber). Inapplications requiring clarity, incorporating into the iPP and EPcopolymer polymer blend a minor fraction of a highly compatiblepropylene copolymer known to have a minimal deleterious effect or even apositive effect on the clarity of blends with polypropylene may providefor such. Compatible propylene copolymers are exemplified bypropylene-ethylene copolymers containing less than 16 wt %, less than 11wt %, or less than 6 wt % ethylene units.

Still yet another exemplary, but non-limiting application of where theiPP and EP copolymer blends made by the fluid phase in-line blendingprocess disclosed herein find application are those where materialsrequiring a combination of stiffness and impact resistance and/or acombination of heat resistance and impact resistance. A polymer blenduseful for these applications are similar in composition to the blendsspecified for impact resistant devices and packages. More particularly,polymer blends useful for this particular application may include from60 to 99 wt % of a stiff iPP blend component and/or a relatively stiff,low comonomer containing propylene copolymer and 1 to 40 wt % of apropylene copolymer containing 5 to 20 wt % of ethylene comonomer, orcomonomer-propylene elastomer (like ethylene-propylene rubber). Thestiffness and heat resistance may be increased by increasing thehomopolymer or stiff copolymer portion of the polymer blend.Correspondingly, the impact resistance may be improved by increasing thepropylene copolymer or ethylene-propylene rubber portion of the blend.The desired balance of product attributes may be accomplished by acareful balancing of the two components.

Still yet another exemplary, but non-limiting application of where theiPP and EP copolymer blends made by the fluid phase in-line blendingprocess disclosed herein find application are those where a deviceand/or package must be sterilized by high temperature and also must besoft and able to withstand impact abuse even at low temperatures.Polymer blends useful for this particular application may include from75 to 99 wt % of one or more stiff iPP homopolymer and/or EP copolymercomponents and 1 to 25 wt % of one or more low to no crystallinitypropylene copolymers, and ethylene-propylene rubbers. Where increasingsoftness of packages and device is desired, one may use a greaterfraction of the one or more soft components in the blend and smallerfraction of the one or more stiff components in the blend. Polymerblends useful for this particular application may also include a majorfraction of the soft components and minor fraction of the stiffcomponents. Hence the range of iPP and EP copolymer blends may include 1to 50 wt % of the stiff polymer component and 50 to 99 wt % of the softpolymer component.

Still yet another exemplary, but non-limiting application of where theiPP and EP copolymer blends made by the fluid phase in-line blendingprocess disclosed herein find application are films which are requiredto melt and form a seal at relatively low elevated temperature yet stillmaintain integrity at much higher temperature. The range of blendcompositions previously specified for soft, elevated temperatureresistant devices and/or packages would apply for this particular typeof film application. Similar relationships between competing propertiesand the relative usages of the relative components would also apply forthis application. More particularly, a greater fraction of the stiffpolymer component may increase the seal integrity at highertemperatures, whereas a greater fraction of the soft polymer componentmay improve seal formation at lower temperatures and seal strength atnormal temperatures.

As will be appreciated by one skilled in the art of polymer engineering,variations to the aforementioned polymer blends and their advantageousapplications may be made without deviating from the spirit of thepolymer blends provided by fluid phase in-line blending processdisclosed herein. Set forth below are further details for composition ofmatter, properties and methods of making the ethylene-propylenecopolymer blend component and the isotactic polypropylene blendcomponent previously described.

In-Line Blending Process Overview

The in-line blending processes disclosed herein relate to making thenovel iPP-EP copolymer polymer blends disclosed above. In particular,disclosed herein are advantageous processes for direct in-line iPP-EPcopolymer blend production in an integrated multi-reactor polymerizationwherein the blending step is achieved downstream of the reactors in aseparator-blending vessel (also referred to as the high-pressureseparator, or as separator-blender). The production of polymer blends inthe polymerization plant is facilitated when the polymer blendcomponents are dissolved in the polymerization system since thesmall-molecule component(s), such as monomer(s) and optionalsolvent(s)/diluent(s) of the polymerization system reduce(s) viscositythus allowing molecular level blending in a low shear process. Hence,using the reactor effluents wherein the polymer blending components arepresent in a dissolved fluid state may be advantageous to downstreamblending operations. The polymerization reactors advantageously may beof the homogeneous supercritical process, the solution process type, ora combination thereof in order to provide the precursor polymer forblending in a dissolved fluid state in the direct reactor effluentssuitable for in-line blending without further processing. Bulkhomogeneous supercritical and bulk solution polymerization processes areparticularly useful for producing blend components due to the simplicityof the monomer recycle loop and due to the enhancements in reactorproductivity and product properties, such as molecular weight andmelting behavior, as will become apparent from the followingdiscussions. The processes disclosed herein can also utilize certainother polymerization reactors making in-line blend components, forexample, in the form of a slurry, wherein the iPP or EP copolymer blendcomponent form solid pellets in a dense fluid polymerization system. Insuch instances, a dissolution stage is added between the polymerizationreactor train and the separator-blending vessel. This dissolution stagetypically consists of a pump followed by a heater to bring the reactoreffluent above the solid-fluid phase transition conditions affording astream that contains the polymer blending component homogeneouslydissolved in the dense fluid polymerization system. In order tofacilitate the dissolution of the polymer pellets, increased shearingmay be applied, which typically is provided by stirring or by pumping.Because of the added processing and investment costs of such reactoroperations, homogeneous polymerization processes, such as homogeneoussupercritical or solution polymerization, are typically cost-advantagedand thus advantageous to produce the in-line polymer blendingcomponents.

The in-line blending process for iPP-EP copolymer blends disclosedherein requires an upstream polymerization process that provides the twoor more blend components in a homogeneous fluid state, wherein at leastone of the blend components is in its supercritical state. Therefore, ifthe polymerization reaction for one component is carried out atconditions that form particles, such as, for example, slurrypolymerization, an additional step is required to bring the in-linepolymer blending component into a dissolved fluid state before feedingthe polymer-containing stream to the separator-blender section of theinvention process (see FIG. 10). This can be accomplished by, forexample, heating the reactor effluent above the solid-liquid phasetransition temperature. However, for simpler and thus lower costoperations, the polymerization reaction is typically carried out atconditions where the product polymer(s) is/are dissolved in the densefluid polymerization system comprising one or more monomers, thepolymeric product(s), and—optionally—one or more inert solvents,and—optionally—one or more scavengers. Fluid-phase operations have somefurther advantages from certain product quality and operation stabilityperspectives since they do not require supported catalysts thatsignificantly increase the ash level of the products and can causefouling and excessive wear of downstream process hardware. The fluidreaction medium may form one single fluid phase or two fluid phases inthe reactor. For more robust and simpler reactor operations, conditionsaffording a single fluid phase in the reactor, i.e. operating above thecloud point conditions, are advantageous.

In one embodiment of the iPP-EP copolymer blending processes disclosedherein, the blending of two or more reactor effluent streams containingthe dissolved polymer blend components occurs simultaneously withproduct separation in a single downstream separator-blending vessel. Theseparator-blender operates at conditions that lead to the formation oftwo fluid phases: the upper one essentially consisting of thelow-molecular weight components of the polymerization systems,predominantly the monomer(s) and the optional solvent(s), while thelower one is a polymer-rich phase. In order to create the conditionsthat lead to the formation of two fluid phases in the separator-blender,the temperatures of the reactor effluents are often first increased toprovide the heat for staying above the solid-fluid phase transitiontemperature of the to-be-formed polymer-rich fluid phase. Afteradjusting the heat contents of the reactor effluents, their pressuresare typically reduced to bring the temperature and pressure of thecombined effluent stream to a condition that corresponds to two fluid(liquid-liquid or supercritical fluid-supercritical fluid) phases in thephase diagram. The blending process may be aided by optional staticmixer(s) downstream of the mixing point of the polymer-containingeffluents but upstream of the separator-blending vessel. The homogeneousfluid blending of the individual polymer components and the separationof the monomer- and polymer-rich phases are accomplished in the samevessel eliminating the need for a separate blending vessel and blendingprocess step. The bulk of the monomer(s) and the optional solvent(s)separated from the polymer is/are then recycled back into thepolymerization reactor bank of the plant.

In another embodiment of the in-line iPP-EP copolymer blending processesdisclosed herein, one or more reactor effluent streams containing thedissolved polymer blend components are fed to independent separators orseparation vessels (also referred to as single-stream high-pressureseparators) upstream of the separator-blending vessel for separation ofa polymer-enriched stream from some fraction of the monomer and theoptional solvent/diluent content of the said streams. Such single-streamhigh-pressure separators deployed upstream of the separator-blendingvessel (high-pressure separator) in essence afford a partial recovery ofthe monomer and the optional solvent present in the reactor effluentthus allowing their recovery and recycle before being mixed withmonomers and optional solvents used in other reactor trains. Suchprocesses may be advantageous by eliminating the need for separatingmixed monomer and optional solvent streams before recycling them to theappropriate reactor trains of the reactor bank. The polymer-enrichedstreams from each of these single-stream separators are blended in oneof a separator vessels that serves both as a separator for one of thereactor trains and as a blender for the entire reactor bank(separator-blending vessel). In this embodiment, the operationconditions of the single-stream separator(s) upstream of theseparator-blending vessel may be adjusted to yield polymer-enrichedstream(s) that still contain(s) enough low molecular weightcomponent(s), such as monomer(s) and optional inert solvent(s) to keepthe viscosity of these streams much below that of the essentially puremolten polymer(s) thus facilitating the mixing of the blending polymercomponents in the separator-blender. The separator(s) feeding theseparator-blending vessel may also serve as buffer vessel(s) affordingan improved control of the blend ratio by compensating for the small butinevitable fluctuations in the production of the individual in-lineblend components. The buffer capacity of these vessels is defined by thevolume between the maximum and minimum levels of the separatedpolymer-enriched lower phase.

As opposed to using a cascade of series reactors for the in-lineblending of iPP and EP copolymer, the blending processes disclosedherein provide for the individual iPP and EP copolymer components of thepolymer blend to be made in a bank of parallel reactors. Such directblend production may be advantageously achieved in polymerizationprocesses that operate in a homogeneous dense fluid phase, i.e. abovethe fluid-solid phase transition limits. The inventive process has atleast one reactor train that operates in the homogeneous dense fluidphase in its supercritical state. Polymerization processes that operatein a homogenous dense fluid phase use either inert solvent(s) ormonomer(s) or their mixtures as a solvent/diluent in their liquid orsupercritical state. Hence, such parallel reactors operate withpolymerization systems in their homogeneous supercritical or in theirliquid state. In both the supercritical and liquid operation modes, theprocess shall be a bulk polymerization process operating with less than40 wt %, or less than 30 wt %, or less than 20 wt %, or less than 10 wt%, or less than 5 wt % of inert solvent present in the reactor, and insome embodiments, essentially free (less than 1 wt %) of inert solvents.In one embodiment of the disclosed process, the reactors operate at bulkhomogeneous supercritical conditions as has been disclosed in U.S.patent application Ser. Nos. 11/433,889 and 11/177,004, hereinincorporated by reference in their entirety.

In another embodiment, one or more of the reactors included in theparallel bank of reactors operate in the homogeneous supercritical stateand one or more of the reactors included in the parallel bank ofreactors operate in the bulk solution state (combination of bulksolution process and homogeneous supercritical process reactors). Bothsolution and homogeneous supercritical polymerization processes providepolymers dissolved in a fluid state, which is required for thedownstream in-line blending of polymers. Both solution and homogeneoussupercritical polymerization processes providing polymers in ahomogeneous fluid state may be performed in a bulk monomer phase usingessentially pure monomer(s) as solvent. The solution process providesfor a polymer-containing liquid phase either in an inert solvent or inthe essentially neat monomer or in their mixture in their liquid state.The homogeneous supercritical process provides for the polymeric fluidstate by dissolving the polymeric product either in an inert solvent orin the essentially neat monomer or in their mixture in theirsupercritical state.

In another embodiment, one or more reactors included in the parallelreactor bank operate in homogeneous supercritical mode and one or morereactor trains operate in the slurry mode (combination of slurry andhomogeneous supercritical or combination of slurry and solutionprocesses). The dense fluid phase(s) of the slurry polymerizationprocess(es) deployed in one or more trains of the invention in-lineblending process can be either in its/their liquid or in its/theirsupercritical state. Before bringing the effluent(s) of the slurrytrain(s) to the separator-blending vessel (high-pressure separator) ofthe in-line blending process of the invention, the effluents are treatedto fully dissolve the slurried polymer blend component. Aside thisdissolution step, the other aspects of the in-line blending processdisclosed herein are not affected by having particle-formingpolymerization reactors in the reactor bank. This embodiment may provideproduct advantages in certain applications due to the ability of theslurry process to produce certain highly crystalline isotactic PP blendcomponents, such as isotactic polypropylene made with Ziegler-Nattacatalysts. It is, however, typically more expensive due to the addedprocessing and investment cost. The optimal choice between the differentreactor configurations of the invention process depends on the targetproduct slate or even on some production site-specific issues, like, forexample, the utilization of existing polymerization facilities. Theoptimal configuration can be determined by standard techniques wellknown in the art of chemical engineering.

The parallel reactor configuration disclosed herein permits forflexibility in independently controlling for each reactor the residencetime, monomer composition and conversion, catalyst choice, and catalystconcentration not available in a series reactor configuration forblending of iPP and EP copolymer blend components. It also makes theindependent control of reaction temperature and pressure easier thusenhancing the control of the polymerization processes yielding theindividual in-line iPP and EP copolymer blend components.

U.S. patent application Ser. Nos. 11/433,889 and 11/177,004 disclose aflexible homogeneous polymerization platform for the homogeneoussupercritical propylene polymerization process (also referred to hereinas the “supercritical process”). In the referred supercritical propylenepolymerization process, polymerization is carried out in a substantiallysupercritical monomer medium, thus it is a bulk homogeneoussupercritical polymerization process. The polymer is in a homogeneouslydissolved state in the reactor and in the reactor effluent thus makingthe reactor effluent suitable for a direct downstream blending operationprior to recovering the polymeric products in their solid pelletized orbaled form. U.S. patent application Ser. Nos. 11/433,889 and 11/177,004also teach that the supercritical polymerization process provides anadvantageous means to the so-called solution processes in its ability toproduce highly crystalline, high molecular weight (i.e. low melt-flowrate) isotactic iPP blend components. Unlike gas phase and slurrypolymerization processes, the supercritical process may also produceethylene-propylene copolymers and iPP blend components with reducedtacticity, and thus reduced polymer melting point without fouling. Aspreviously referenced, U.S. patent application Ser. Nos. 11/433,889 and11/177,004 are incorporated by reference in their entirety herein.

Advantageous iPP-EP copolymer blends are often composed of a blend of(a) highly crystalline component(s) and (a) low crystallinitycomponent(s). Slurry and gas phase polymerization processes may providefor high molecular weight, highly crystalline polymers, but not for lowcrystallinity products because the polymer pellets stick togethercausing fouling of the reactor. Fouling often makes the production ofsoft materials, such as, for example, ethylene propylene copolymerscommercially impractical, particularly when the ethylene content exceedsapproximately 9 to 10 wt %. In contrast, solution polymerizationprocesses has no such limitation and may provide for low crystallinityproducts because the polymer is present in solution in the reactor, andtherefore cannot foul it. However, the solution process has limitationsin producing highly crystalline, high molecular weight products withhigher melting point. One particularly relevant limitation of thesolution process is that it typically cannot produce high MW productsthat also have high melting point, and if it could, such products tendto crystallize in the reactor and cause fouling. In contrast, thehomogeneous supercritical process may provide for both highcrystallinity/high melting point and low crystallinity/low melting pointpolymers without fouling. It also generates the polymer blend componentsin a dissolved state in the polymerization system allowing directblending without the need for a dissolution step. These attributes makeit a particularly advantageous polymerization process for the in-lineiPP-EP copolymer blending processes disclosed herein. Notwithstanding,any combination of polymerization processes operating with densepolymerization systems may be deployed in the in-line blending processesdisclosed herein as long as at least one of the reactor trains operateswith a homogeneous polymerization system. Homogeneous operation isensured by operating above the solid-fluid phase transition point,advantageously not lower than 10 MPa below the cloud point of thepolymerization system.

The monomers for use in the bank of parallel reactors disclosed hereinare propylene, ethylene, and optional one or more comonomers comprisingfour or more carbon atoms. Non-limiting exemplary optional one or morecomonomers comprising four or more carbon atoms include butene-1,pentene-1, hexene-1, octene-1, decene-1, dodecene-1, and combinationsthereof. Exemplary, but not limiting, non-polymerizing (inert) fluidcomponents serving as diluents/solvents include light paraffinic andaromatic hydrocarbons and their blends, such as butanes, pentanes,hexanes, heptanes, octanes, toluene, xylenes, cyclopentane, cyclohexane,fluorocarbons, hydrofluorocarbons, etc.

The conditions in the polymerization reactors of the aforementionedolefin polymerization process may be established such that the entirereactor content, including the monomer(s), optional non-polymerizingfluid, catalyst system(s), optional scavenger(s) and polymeric products,is in a homogeneous fluid, and advantageously in a single homogeneousfluid state. In one form, the conditions in at least one of the reactorsof the aforementioned process are set such that the contents are intheir supercritical fluid state, and advantageously in a singlehomogeneous supercritical fluid state.

The upper limit for temperature is determined by the product propertiesthat are strongly influenced by the reaction temperature. Since oftenpolymers with higher molecular weights and/or higher melting points aredesired, high polymerization temperatures (>250° C.) are generally notadvantageous. Increased temperatures can also degrade most knowncatalytic systems, providing another reason for avoiding excessivepolymerization temperatures. At the current state of the art ofpolymerization, polymerization temperatures above 350° C. are notrecommended. For the slurry polymerization processes, the uppertemperature limits of polymerization are also influenced by thesolid-fluid phase transition conditions since running near thesolid-fluid phase transition line leads to fouling. For that reason,slurry operations not higher than 5° C. below the solid-fluid phasetransition are advantageous, not higher than 10° C. below thesolid-fluid phase transition are particularly advantageous.

The lower limits of reaction temperature are determined by the desiredpolymer properties. Lower temperatures generally favor highercrystallinity and higher molecular weight. For homogeneouspolymerization processes, the lower limits of reaction temperature arealso determined by the solid-fluid phase transition temperature. Runningthe reactors below the solid-fluid phase transition temperature of thereaction mixture may lead to operation problems due to fouling. For theproduction of highly crystalline polypropylenes (melting peaktemperatures >150° C.) in bulk homogeneous supercritical polymerizationprocesses, the minimum operating temperature is about 95 to 100° C. Inthe production of lower melting copolymers, such as ethylene-propylenecopolymers, significantly lower reactor temperatures, e.g., 90° C. oreven lower, may be readily used without fouling. The application ofcertain inert solvents may further reduce the minimum operationtemperature of the fouling-free operation regime, although, as discussedearlier, the substantial presence of inert solvents also tends to limitthe product molecular weight and often the melting peak temperature. Italso increases production cost due to the need for solvent handling.

The critical temperature and pressure of the polymerization systems aredifferent from the critical values of pure components, and thussupercritical operations at temperatures lower than the criticaltemperature of pure propylene and C₄ plus monomers (e.g., 92° C. forpropylene) are possible and disclosed herein. Additionally,near-amorphous and amorphous materials with low melting points may beproduced without fouling even below the critical temperature of thereactor blends, i.e., at temperatures that correspond to the condensedliquid state of the polymerization system in the reactor. In theseinstances, the operation temperature may be below the bubble point ofthe reaction mixture and thus the reactor operates at what is oftenreferred to as liquid-filled conditions. In some instances, suchoperation mode could be desired to achieve high molecular weight (MW)and thus low melt flow rate (MFR), particularly in the manufacture ofcopolymers, such as propylene-ethylene copolymers. Thus, reactoroperations under conditions at which the polymeric products aredissolved in the monomer or monomer blend present in its liquid state,also known as bulk solution polymerization, are also disclosed herein.

Total Monomer Conversion for Homogeneous Fluid Phase Polymerizations:

Increasing the conversion of the total monomer feed in a single-pass inthe individual reactor trains of the parallel reactor bank can reducethe monomer recycle ratio thus can reduce the cost of monomer recycle.Increasing monomer recycle ratios (i.e., the ratio of recycled/totalmonomer feed to the reactor train) require the treatment and recycle oflarger monomer volumes per unit polymer production, which increasesproduction cost. Therefore, higher monomer conversion (lower recycleratios) often provides for improved process economics. However, becausehigh polymer content in the polymerization system, particularly inhomogeneous polymerization systems, yields high viscosities, whichcorrespondingly may make reactor mixing, heat transfer, and downstreamproduct handling difficult, the monomer conversion in a single pass haspractical operation limits. The viscosity of monomer-polymer blends andthus the practical conversion limits can be readily established bystandard engineering methods known in the art (M. Kinzl, G. Luft, R.Horst, B. A. Wolf, J. Rheol. 47 (2003) 869). Single-pass conversionsalso depend on operating conditions and product properties. Therefore,monomer conversion may also be constrained by the desire to increase themolecular weight of the blend component made in the given reactor train.Exemplary, but not limiting, total monomer single pass conversions arebelow 90%, more particularly below 80% and still more particularly below60%. Total monomer conversion is defined as the weight of polymer madein a reactor or in a reactor train divided by the combined weight ofmonomers and comonomers in the feed to the reactor or reactor train. Itshould be understood that while high total monomer conversion is oftenlimited by product viscosity or by product property targets, theconversion of some highly reactive monomer components present in somemonomer feed blends may be higher than 90%. For example, the single-passconversion of ethylene in ethylene-propylene or in ethylene-higherolefin feed blends may be nearly complete (approaching 100%) and isdisclosed herein.

As mentioned above, another factor limiting the total monomer conversionis the MW-decreasing effect of conversion. Therefore, the production ofpolymer blend components with high MW requires the moderation of monomerconversion in a single pass beyond that of what viscosity and otherpractical operation considerations would dictate. Hence, for theproduction of blend components with high molecular weight (particularlythose with higher than >200 kg/mol weight-averaged molecularweight—M_(w)), the total monomer conversion may need to be below 30%.Again, the conversion of some highly reactive components in a monomerfeed blend may be higher, and may even approach 100%.

The single-pass conversion in the polymerization reactors disclosedherein may be adjusted by the combination of catalyst concentration andtotal feed flow rate. The total feed rate determines the averageresidence time (in a back-mixed reactor equal to the reactor volumedivided by the total volumetric flow rate of the effluent). The sameconversion may be achieved at lower residence time by increasing thecatalyst concentration in the feed and vice versa. Lower catalystconcentration may reduce catalyst cost, but may also reduce volumetricproductivity thus requiring higher residence times, and ultimately alarger reactor and thus higher investment cost for the same polymerproduction capacity. The optimum balance between residence time/reactorvolumes and catalyst concentration may be determined by standardengineering methods known in the art. A wide-range of iPP and EPcopolymer blend components may be produced in the reactors disclosedherein at reactor residence times ranging from 1 sec to 120 min,particularly from 1 sec to 60 min, more particularly from 5 sec to 30min, still more particularly from 30 sec to 30 min, and yet still moreparticularly from 1 min to 30 min. In yet another form of the in-lineblending process embodiments disclosed herein, the residence time in thereactors disclosed herein may be less than 120, or less than 60, or lessthan 30, or less than 20, or less than 10, or less than 5, or less than1 minute(s).

In certain embodiments, at least one of the reactor trains of thedisclosed process operates at supercritical conditions advantageously athomogeneous supercritical conditions, or bulk homogeneous supercriticalconditions. The residence times in the supercritical polymerizationreactors, particularly in the bulk homogeneous supercritical reactorsdisclosed herein are generally lower than the residence times insolution, gas phase, and slurry processes due to the high reaction ratesachieved at the conditions of the supercritical polymerization process.In-line blending processes disclosed herein applying bulk homogeneoussupercritical polymerization often choose residence times between 1 and60 min, and more particularly between 1 and 30 min.

The polymerization reactors of the in-line blending processes disclosedherein may be grouped into reactor(s) making a single blendingcomponent, called the reactor train. The reactors of the parallelreactor trains producing all the polymer blend components are referredto as reactor bank. The reactors in the individual trains and in theentire bank can be of any type useful for making polymers (for a reviewof different polymerization reactors see Reactor Technology by B. L.Tanny in the Encyclopedia of Polymer Sci. and Eng., Vol. 14, H. F. Market al., Eds., Wiley, New York, 1988, and J B P Soares, L C Simon in theHANDBOOK OF POLYMER REACTION ENGINEERING, T. Meyer and J. Keurentjes,Eds., Wiley-VCH, Weinheim, 2005, p. 365-430.) and can be constructed thesame way or can be different. The optimal reactor type and configurationcan be determined by standard techniques well known in the art ofpolymer reactor engineering.

It should be recognized that the catalytic activity and thus thevolumetric productivity in the individual reactors may be different. Ifthe reactor effluents for in-line blending are directly blended, thecatalytic activity and the volumetric productivity may determine thereactor sizes required for the production of the individual polymerblend components. In order to reduce cost, a single plant may need toproduce several polymer blends with different polymer components blendedover a range of blend ratios. Consequently, a parallel reactor bank willoften have reactors of different sizes allowing for a flexible and thusmore cost effective configuration for the production of differentpolymer blend grades. The optimal reactor volumes may be determined fromthe combination of the composition of the target polymer blends and thevolumetric reactor productivity data using optimization methods known inthe art of chemical engineering.

In commercial practice, reactor productivity tends to vary to somedegree, which in turn may lead to the corresponding level of variabilityin polymer blend ratios. In one embodiment, buffer tanks may be added tothe process downstream of the reactors comprising the bank of parallelreactors, but before the polymer mixing or blending point to compensatefor the fluctuations of the volumetric productivity in each reactortrain producing the individual blend components (see for example FIG.4). The buffer tanks may improve the compositional control of the finalproduct blends by homogenizing the individual reactor effluents and byallowing a more independent metering of the polymer blend components.When an individual reactor train effluent is stored in the buffer tankin its liquid state at a pressure below its bubble point, essentiallythe entire volume of the buffer tank is available for compensating forthe differences in the blending and production rates. However, when theindividual reactor effluent is stored in the buffer tank in itssupercritical state or in its liquid state but at pressures above itsbubble point, the dense liquid or supercritical fluid fills the entiretank. In such operation modes, the buffering capacity, i.e. the capacityto deviate from the instant reactor flow rate, is more limited and isassociated with the pressure/density changes allowed in the buffer tankand with the size of the buffer tank. In the latter case, the processstreams may be driven by a gradual pressure drop downstream of thereactor to avoid the cost of installing and operating booster pumps.However, booster pumps may be alternatively installed and operatedwithin the process to increase the pressure range and thus the bufferingcapacity of the system. When no booster pumps are deployed, the pressureof the buffer tank should be lower than that of the reactor, but higherthan that of the lines downstream of the blending point.

Apparently, while feasible, controlling this kind of buffer system isdifficult and it is not very efficient. Thus, in another embodiment,when the individual reactor effluent is stored in the buffer tank in itssupercritical state or in its liquid state but at pressures above itsbubble point, the conditions in the buffer tanks may be set to achievefluid-fluid phase separation (separator-buffer tank operation).Buffering in this mode can be achieved by allowing the fluid level ofthe denser polymer-rich phase to move up and down between the minimumand maximum levels allowed for the desired level of separation whiletaking the monomer-rich upper phase out of the separator buffer via apressure control valve. One skilled in the art can see that thisoperation mode is analogous to the operation of a buffer tank filledwith a liquid phase containing the polymeric product and a vapor phasecontaining the more volatile components, such as monomer(s) andsolvent(s). In the supercritical regime, the upper phase is apolymer-lean supercritical fluid, while the lower phase is apolymer-rich supercritical fluid, the latter of which can be withdrawnfor blending at a controlled rate required for making a constant blendratio, independent of the short-term fluctuations in the productionratios of the individual blend components. A similar analogy may bederived for liquid-filled operations. The polymer content, and thus theviscosity of the polymer-rich phase can be controlled by properlyadjusting the temperature at constant pressure or by adjusting thepressure at constant temperature in the separator-buffer tank(s). Inthis embodiment, the polymer-rich effluent(s) of the separator-buffertank(s) are combined with the direct, unseparated effluent of one of thereactor trains upstream of the separator-blending vessel that recoversthe monomer of the direct reactor effluent as a supernatant and thein-line polymer blend as the bottom phase. In this particularembodiment, one of the separators serves as a separator-blender, whilethe rest of the separators serve as separator-buffers.

In another embodiment of the processes disclosed herein, polymeradditives may be added to the iPP-EP copolymer blend at ratios of up to40 wt %, or up to 30 wt %, or up to 20 wt %, or up to 10 wt %, or up to5 wt % to further improve product quality and product properties.Exemplary, but not limiting polymer additives, include specialtypolymers including polar polymers, waxes, polyalfaolefins, antioxidants,plasticizers, clarifiers, slip agents, flame retardants, heat and uvstabilizers, antiblocking agents, fillers, reinforcing fibers,antistatic agents, lubricating agents, coloring agents, foaming agents,tackifiers, organically modified clays such as are available fromSouthern Clay, and masterbatches containing above components. Hence, oneor more polymer additive storage tanks containing liquid, molten, ordissolved polymer components and polymer additives may be added to theprocesses disclosed herein. If solvent(s) is used in these polymeradditive storage tanks, it may be advantageously the same as used in thepolymerization reactors previously described in order to avoid anincrease in separation costs in the solvent recovery and recycle sectionof the process. For example, when the polymer synthesis process isperformed in supercritical propylene, the off-line produced polymeradditives may also be advantageously dissolved in supercriticalpropylene. However, other solvent(s) or solvent-free introduction may beused with the polymer additives. Solvent-free introduction of thepolymer additive components may be used when the additive component isbrought into its molten state or when the additive component is a liquidat ambient temperatures.

The homogeneous supercritical polymerization and the solutionpolymerization processes are particularly suitable for providing theproduct polymer in a dissolved fluid state. In one particularembodiment, the supercritical polymerization process is performed in thesubstantial absence of an inert solvent/diluent (bulk homogeneoussupercritical polymerization) and provides the product in a dissolvedsupercritical state for the downstream in-line separation-blendingprocess. More particularly, the supercritical polymerization ofpropylene is performed in the substantial absence of an inertsolvent/diluent (bulk homogeneous supercritical propylenepolymerization) and provides the product in a dissolved supercriticalstate for the downstream in-line separation-blending process.

The total amount of inert solvents is generally not more than 40 wt % inthe reactor feeds of the invention process. In some embodiments, wherethe feed essentially comprises the monomer or monomer blend, like forexample, bulk slurry, or bulk supercritical, or bulk solutionpolymerizations, the minimization of solvent use is desired to reducethe cost of monomer recycling. In these cases, the typical solventconcentration in the reactor feed is often below 40 wt %, or below 30 wt%, or below 20 wt %, or below 10 wt %, or below 5 wt %, or even below 1wt %. In one form disclosed herein, the polymerization system comprisesless than 20 wt % aromatic hydrocarbons and advantageously less than 20wt % toluene. In another form disclosed herein, the polymerizationsystem comprises less than 40 wt %, or less than 30 wt %, or less than20 wt % saturated aliphatic hydrocarbons and advantageously less than 40wt %, or less than 30 wt %, or less than 20 wt % of decanes, or nonanes,or octanes, or heptanes, or hexanes, or pentanes, or butanes, orpropane, or their mixtures.

Fluid Phase In-Line Blending Process Configuration

The fluid phase in-line iPP-EP copolymer blending process disclosedherein may have different detailed process configurations. For example,the number of parallel reactor trains and their configurations in theparallel reactor bank may be varied. Typically, each reactor trainserves to produce either the iPP or the EP copolymer blend component. Agiven train of the parallel reactor bank may be configured as a singlereactor or two or more reactors in series. From a practical commercialplant design standpoint, however, there should be a minimum number ofreactors for a given train of the parallel reactor bank in order to makea given polymer blend component. Generally, not more than ten seriesreactors are utilized and more particularly not more than three seriesreactors are generally utilized in a given reactor train. The number ofparallel trains in the parallel reactor bank may be two, three, four orfive or more. The number of reactors in the parallel reactor bank may beany number, although for economic reasons the number of reactors shouldbe maintained as low as the desired product grade slate and plantcapacity allows. The optimum number of parallel reactor trains (alsoreferred to as legs of the reactor bank) may be determined by standardchemical engineering optimization methods well known in the art. Mosttypically, the polymerization-blending plant will have two or threeparallel polymerization reactor trains or legs in the reactor bankproducing product blends with the corresponding number of in-linepolymer blend components. However, more than three parallelreactors/legs may be employed if the production of the target productblends so requires. Besides the in-line polymer blend components, thefinal polymer blends often contain additives and modifiers that are notproduced within the same polymerization process. Therefore, it should beunderstood that the number of components in the final product blendtypically is higher than the number of reactor trains or the number ofin-line polymer blend components.

The fluid phase in-line iPP-EP copolymer blending process disclosedherein may also optionally incorporate other polymers, and polymeradditives that were produced outside the reactor bank of the processesdisclosed herein. The optional other polymer and polymer additivecomponents may first be transferred into solution or molten fluid statebefore being blended with the in-line produced polymer blend components.These other polymer and polymer additive components may be stored inpolymer additive storage tanks containing liquid, molten, or dissolvedpolymer components and polymer additives prior to being transferred andmetered to the separation-blending vessel or to a mixing point upstreamor downstream of the separation-blending vessel. Polymer and polymeradditive components may be accurately metered to the blending vessel orto another mixing point by one or more pumps or if the downstreampressure is lower, through the use of one or more pressure letdownvalves. The optional additives and modifiers can be mixed into theproduct upstream of or directly in the separator-blending vessel ordownstream of the separator-blending vessel of the processes disclosedherein. In order to simplify monomer treatment in the monomer recycletrain and thus to reduce the cost of monomer recycle, it is oftenadvantageous to add the additives and modifiers downstream of theseparator-blending vessel. In such embodiments, the additives andmodifiers may be mixed with the in-line produced polymer blend indedicated pieces of equipment or in the hardware of the productfinishing section of the processes disclosed herein, for example, in thedevolatizer extruders.

Referring to FIG. 2, in one exemplary embodiment of the fluid phasein-line iPP-EP copolymer blending process disclosed herein, theeffluents of all parallel reactor trains in the reactor bank are broughtinto a single separator-blending vessel (also referred to as ahigh-pressure separator). The separator-blender separates some or mostof the low molecular weight components, such as monomer(s), optionalsolvent(s), and product lights (monomer-rich phase) from thepolymer-rich phase, but also blends the iPP and EP copolymer blendcomponents made in different reactor trains of the invention processforming a polymer-rich blend effluent. This mode is also referred to assingle separation vessel operation. The number of reactor trains in theparallel bank may be 2, 3, 4, and up to n. The effluents of thedifferent reactor trains and thus the individual polymer components arecombined upstream of the separation vessel after individual pressure letdown valves, which function to bring the reactor train effluents to thecommon pressure of the separator-blending vessel. Catalyst killingagent(s) may be optionally introduced prior to or into theseparator-blending vessel to minimize further polymerization outside thepolymerization reactors. Optionally, one or more static mixerspositioned before the separator-blending vessel, but downstream of themixing point, may also be utilized to enhance mixing between the reactortrain effluents. Optionally, some or all reactor train effluents may beheated before the pressure letdown (not shown in FIG. 2) in order tomaintain the temperature in the downstream lines and in theseparation-blending vessel at the desired value, i.e., above thesolid-fluid phase transition temperature of the polymer-rich phase ofthe separator-blender, but below the cloud point of the combinedeffluents entering the separator-blending vessel to allow the formationof a polymer-rich denser fluid phase and a monomer-rich lighter fluidphase.

After the combined reactor train effluent streams enter theseparator-blending vessel, monomer recycle (monomer-rich phase) emergesfrom the top of the separator-blending vessel and a polymer-rich blendemerges from the bottom of the vessel. The polymer-rich blend may thenbe conveyed to a downstream finishing stage for further monomerstripping, drying and/or pelletizing. As described earlier, modifiersand additives may also be introduced either before or into theseparator-blending vessel or downstream of it. A downstream introductionof these modifiers and additives typically simplifies monomer recycle,and is thus advantageous. In this embodiment, the singleseparator-blending vessel serves as both a separator and a blender. Oneadvantage of this exemplary embodiment is the utilization of a singleseparator-blending vessel, which provides for process simplicity becauseit functions for both separation and blending purposes. One disadvantageof this exemplary embodiment is that because all reactor train effluentstreams are combined, the recovered monomer stream from theseparator-blending vessel may need to be separated prior to recycle tothe individual reactor trains in the parallel bank of reactors. Insummary, this embodiment may be simpler and thus lower cost in theseparator section, but may be more costly in the monomer separation andrecycling loop section of the process.

FIG. 3 depicts an alternative exemplary embodiment of the fluid phasein-line iPP-EP copolymer blending process disclosed herein in which eachreactor train has a dedicated separator vessel with the exception of onereactor effluent train where all polymer-rich phases from the otherreactors are combined in a high-pressure separator that also serves as ablending vessel (also referred to as multiple separation vesseloperation). In this embodiment, for all but one of the reactor trains(all but train n in FIG. 3), the single-stream high-pressure separatorserves as a separator to separate a polymer-enriched phase from amonomer-rich phase in the reactor effluent stream. In order to keep thecontent of low molecular weight components higher and thus to keep theviscosity of the polymer-enriched phase lower, the single-streamhigh-pressure separators dedicated to the individual reactor trainsoften operate at a somewhat higher pressure than the one downstreamhigh-pressure separator that serves both as a separator and as a blender(separator-blender). Therefore, there is an optional pressure letdownbetween these separators and the separator-blender. For the onehigh-pressure separator (separator-blender) where the other polymer-richphases are combined and the reactor train effluent from one of thereactor trains is introduced (reactor train n in FIG. 3), the separatorserves both iPP-EP copolymer blending and product-feed separatingfunctions. Catalyst killing agent may be optionally introduced prior toor into each separator vessel, including the separator-blender tominimize further polymerization outside the polymerization reactors.Optionally, one or more static mixers positioned before theseparator-blending vessel, but downstream of the mixing point may beutilized to enhance mixing between the polymer-rich phases of thereactor trains and the reactor train effluent of the reactor trainassociated with the separator-blender. Optionally, some or all reactortrain effluents may be heated before the first pressure letdown (notshown in FIG. 3) in order to maintain the temperature in the downstreamlines and in the separators, including the separation-blending vessel,at the desired value, i.e., above the solid-fluid phase transitiontemperatures of the polymer-rich phases but below the cloud point of thestreams entering the separators, including the separator-blender, toallow the formation of polymer-enriched or polymer-rich denser fluidphases and monomer-rich lighter fluid phases. The process of thisembodiment may be advantageous in the production of polymer blends thatinclude different homopolymers or homopolymer(s) and copolymer(s) asblend components. In this embodiment, the homopolymerization train(s)has/have its (their) own separator(s) and the copolymerization train (orone of the copolymerization trains in case of more than one copolymertrains used) serves as a blender. The monomer(s) recovered in theseparator(s) dedicated to individual reactor train(s) may be recycled tothe corresponding reactor train(s) without the complex separation fromother monomers as was associated with single separation-blending vesseloperation previously described. Hence, one advantage of this embodimentis that monomer recycle is simplified and thus affords lower cost in themonomer recycle loop. While multiple separation vessel operationincreases cost in the separator section, it adds flexibility in themonomer recycle loops. In summary, this embodiment may be morecomplicated and higher cost in the separator section, but may be simplerin the monomer recycle loops.

Since both embodiments of FIGS. 2 and 3 serve the same function ofpolymer blending and separation of the polymer-rich from themonomer-rich phases, the choice between them is driven by the economicsof a given plant producing a given product slate and may be determinedby standard engineering optimization techniques known in the art.

FIG. 4 presents another alternative exemplary embodiment of the fluidphase in-line iPP-EP copolymer blending process disclosed herein inwhich is provided a dedicated buffer tank in which no phase separationoccurs for each reactor train and in which the reactor train effluentsare combined in a single separator-blending vessel (also referred to assingle separation vessel operation with buffer tanks). Each of the nparallel polymerization reactor trains in the reactor bank is providedwith its own buffer tank to enable the fine-tuning of the mixing ratioof the blend components. Pressure let down valves may be positioned onthe inlet and outlet side of each buffer tank to control the in-linepolymer blend component flow. Optionally, the reactor effluents may beheated to maintain the desired temperature in the downstreamseparator-blender as described above. Catalyst killing agent may beoptionally introduced prior to or into each buffer tank to minimizefurther polymerization outside the polymerization reactors. Optionally,one or more static mixers positioned after the mixing point but beforethe separation vessel for blending may be utilized to enhance mixingbetween the reactor effluents being fed from the buffer tanks. Incomparison to the single separation vessel operation of FIG. 2, thisalternative exemplary embodiment allows for more precise control of theblend ratio and quality but without the benefit of dedicated monomerrecovery provided by the configuration depicted in FIG. 3. As previouslydiscussed, this embodiment may improve the control of product blendratio and hence product quality, but its buffer capacity may be limited.

An alternative design employing buffering capability is depicted in FIG.5. FIG. 5, a variation of the multiple separation vessel operationdepicted in FIG. 3, and an advantageous version of the buffer-onlyoperation shown in FIG. 4, presents yet another alternative exemplaryembodiment of the fluid phase in-line iPP-EP copolymer blending processdisclosed herein. In this exemplary embodiment the single-streamhigh-pressure separators dedicated to the individual reactor trains alsoserve as buffer tanks. Referring to FIG. 5, for all reactor trains butn, the reactor train effluent is fed to a dual-purpose separator-bufferfor both separation of the polymer-rich phase from the supernatantmonomer-rich phase and storage of polymer-rich phase prior to conveyanceto a downstream blending separator. These single-stream separatorsdedicated to individual reactor trains afford buffering by allowing thelevel of the denser polymer-rich phase to move between an upper and alower limit. This buffer capacity allows for the correction in thepotential fluctuations in the production rates of the individual in-lineblend components and thus provides a means for a more precise control ofthe polymer blend ratio. For reactor train n, the high-pressureseparator (separator-blender) functions to separate the polymer-richphase from the monomer-rich phase for the reactor effluent from reactorn and also to blend the polymer-rich phases from all reactors (1, 2,through n in FIG. 5). From a blend control point of view, there is nobuffering for the in-line component n, and thus all other blendcomponent flows to the separator-blending vessel, and ultimately theirproduction rates, are controlled by the production rate in reactor trainn in order to maintain the desired blend ratios. Catalyst killing agentmay be optionally introduced prior to or into each separator vessel tominimize further polymerization within the separator. Optionally, one ormore static mixers positioned before the separation vessel for blendingmay be utilized to enhance mixing between polymer-rich phases of thereactors and the reactor effluent of the reactor associated with theblending separator. For heat and pressure management, the sameconsiderations, configurations, and controls may be applied as describedfor the previous embodiments. As in all process configurations, optionalmodifiers and additives may be introduced either prior or into theseparator-blending vessel or downstream of it.

FIG. 6 presents yet another exemplary embodiment of the fluid-phasein-line iPP-EP copolymer blending process disclosed herein in which oneof the parallel polymerization trains (train 1 in FIG. 6) produces thepolymer blending component (iPP or EP copolymer) in the form of solidpellets, i.e. operates in the slurry polymerization regime. Thus inorder to bring the polymer into a dissolved state before in-lineblending, the reactor effluent is brought into a heated stirred vessel.In order to keep the entire reactor effluent in a dense fluid phase, thepressure of the reactor effluent is increased by a slurry pump. Slurrypolymerization typically operates at lower temperatures thansupercritical and solution polymerizations and thus may afford productswith higher molecular weight and melting peak temperatures, which mayprovide advantages in certain polymer blend applications. However, thedissolution of polymer pellets adds cost and tends to be prone tofouling and other operational issues. Other aspects of the in-lineblending process disclosed herein, such as catalyst killing, additiveblending, heat and pressure management, as described in the previouslydescribed embodiments, apply hereto as well.

FIG. 7 presents still yet another exemplary embodiment of the fluidphase in-line iPP-EP copolymer blending process disclosed herein inwhich one or more optional polymer and/or more polymer additive storagetanks may be added to the process for the storage and metering of otherfluid polymers and polymer additives to the blending vessel. Optionalpump(s) may be used to convey the polymer(s) or polymer additive(s) tothe separator vessel for blending. Note that FIG. 7 presents theparticular embodiment wherein the one or more optional polymer and/ormore polymer additive storage tanks are added to the singleseparation-blending vessel operation with buffer tanks configuration ofFIG. 4. However, the one or more optional polymer and/or one or morepolymer additive storage tanks may be added to the processes depicted inFIG. 2, FIG. 3, and FIG. 5 without deviating from the spirit of thefluid phase in-line blending process disclosed herein. Similarly,optional off-line produced polymers, modifiers and additives may beintroduced in any part of the polymer finishing section or in adedicated section prior to the product finishing section of the processdisclosed herein. Other aspects of the in-line blending processdisclosed herein, such as catalyst killing, additive blending, heat andpressure management, as described in the previously describedembodiments, apply hereto as well.

As will be appreciated by one skilled in the art of chemicalengineering, the process schematic details of the design of the fluidphase in-line blending process in terms of reactor configuration,separator configuration, valving, heat management, etc. may be setdifferently without deviating from the spirit of the fluid-phase in-lineblending process disclosed herein. The choice between differentembodiments of the processes disclosed herein will be driven by productperformance requirements and process economics, which can be readilydetermined by standard engineering techniques. However, the in-lineblending processes disclosed herein are advantageous relative to theprior art by the virtue of reduced blending cost due to savings ininvestment and operation costs, and enabling well-controlled andcost-effective molecular-level blending to yield enhanced polymer blendperformance.

The processes disclosed herein provide an effective recycle pathway forhomogeneous supercritical olefin polymerization, an example of which isbulk homogeneous supercritical propylene polymerization (SCPP). As willbe discussed in more detail below, the efficient separation of monomerand polymer is achieved by advantageously utilizing the cloud pointpressure and temperature relationships for the relevant(polymer/olefinic monomer) or (copolymer/olefinic monomer blend); e.g.(polypropylene/propylene monomer), (ethylene-propylenecopolymer/ethylene-propylene monomer blend), etc. mixtures.

For illustration, cloud point curves are shown in FIGS. 8 to 22 forthree different polypropylene samples having different molecular weightsand crystallinities dissolved in propylene (at 18 wt %). (Achieve 1635PP is a commercially available metallocene-catalyzed isotacticpolypropylene having a Melt Flow Rate, MFR, (I₁₀/I₂-ASTM 1238, 230° C.,2.16 kg) of 32 g/10 min available from ExxonMobil Chemical Company,Houston, Tex. ESCORENE PP 4062 is a commercially available isotacticpolypropylene having an MFR of 3.7 g/10 min, available from ExxonMobilChemical Company, Houston, Tex. PP 45379 is an isotactic polypropylenehaving an MFR of 300 dg/min produced using a supported metallocene in aslurry polymerization process.

Monomer Recycle To Parallel Reactor Trains:

As disclosed in U.S. Patent Application No. 60/905,247, filed on Mar. 6,2007, incorporated herein in its entirety by reference, some forms ofthe present disclosure also provide for simplified recycle methods forthe monomers emerge unconverted from the parallel reactor trains. Inparticular, the simplified monomer recycle methods are applicable foruse with said fluid-phase in-line polymer blending processes in whicheach monomer component fed to a first group of one or more reactortrains of the said in-line blending processes (G1) is also present inthe feed of a second group of one or more trains of the said in-lineblending processes (G2) so that when the monomer pool of the said firstgroup of trains (G1) is combined with the monomer pool of the secondgroup of trains (G2), the said combined monomer pool and the monomerpool of the second group of trains (G2) are the same. Stating itdifferently, when the effluents (or reduced effluent streams derivedfrom the effluents) of the said first group of reactor trains (G1) arecombined with the effluents of the said second group of reactor trains(G2), the combined effluent stream essentially contains only monomersthat are present in the feed of the said second group of reactor trains(G2). Stating it yet another way, the effluents (or reduced effluentstreams derived from the effluents) of the said first group of reactortrains (G1) essentially do not introduce new monomer components into therecycled effluents of said second group of reactor trains (G2) when theeffluent streams of G1 and G2 are combined. In a mathematical form,these conditions can be described as follows:N(G1+G2)=N(G2) and N(G1)≦N(G2)where N(G1+G2) is the number of monomers in the combined monomer pool ofthe first and second group of reactor trains of the in-line fluid phasepolymer blending process; N(G1) and N(G2) are the number of monomers inthe monomer pool of the first (G1) and second (G2) group of reactortrains of the in-line fluid phase polymer blending process,respectively. The monomer pools present in the individual reactor trainsof G1 can be the same or different. However, the monomer pools presentin the individual reactor trains of G2 are always the same, although themonomer concentrations or monomer ratios may be different (but may alsobe the same). The number of reactor trains both in the first and in thesecond groups of reactor trains (G1 and G2) can be one or more than one.In practice, the number of reactor trains belonging to the first groupof reactor trains of the in-line fluid phase polymer blending process(G1) can be one, two, three, four, five, or more. Similarly, the numberof reactor trains belonging to the second group of reactor trains of thein-line fluid phase polymer blending processes (G2) can also be one,two, three, four, five, or more. It should be understood that as allreactor trains of the in-line fluid phase polymer blending processesdisclosed herein, the one or more reactor trains of G1 are configured inparallel relative to the one or more reactor trains of G2. The G1 and G2reactor trains are also fluidly connected to one another. When theabove-stated conditions for the monomer pools are met in the in-linefluid phase polymer blending processes disclosed herein, the simplifiedmonomer recycle methods disclosed in U.S. Patent Application No.60/905,247 are applicable to the present disclosure. In all embodimentsof the simplified recycle processes, the monomer recycle streamsrecovered from the product streams of G1 before mixing them with any ofthe effluents of G2 are recycled to G1 while the monomer recycle streamsrecovered from the mixed polymer-containing streams of G1 and G2 arerecycled to G2. Since the mixed streams that contain monomers originatedboth from G1 and G2 are recycled to G2, the simplified monomer recyclemethods also ensure that the monomer component recycle rates in therecycle stream originated from the combined G1 and G2 product-containingstreams and sent to G2 are not higher than the desired monomer componentflow rates in the composite feed of G2.

The simplified recycle methods described above and in U.S. PatentApplication No. 60/905,247 are particularly advantageous to the in-lineblending processes for producing iPP and EP copolymer blends disclosedherein because the propylene monomer is present in each of the two ormore parallel reactor trains. For example, if one parallel reactor trainpolymerizes isotactic polypropylene, and a second parallel reactor trainpolymerizes ethylene-propylene copolymer, the unreacted propylenemonomer from the first reactor train may be combined with the unreactedpropylene and ethylene monomers from the second parallel reactor trainand recycled back to the second parallel reactor train using thesimplified monomer recycle methods disclosed herein.

Isotactic PP and EP Copolymer Catalyst System Overview

The in-line process for blending iPP and EP copolymer blend componentsdisclosed herein may utilize any number of catalyst systems (alsoreferred to as catalysts) in any of the reactors of the polymerizationreactor section of the process. The in-line process for blendingpolymers disclosed herein may also utilize the same or differentcatalysts or catalyst mixtures in the different individual reactors ofthe reactor bank of the present invention. It should be understood thatby using different catalyst systems we mean that any part of thecatalyst system can vary and any combination is allowed. For example,the invention process may use unsupported catalyst systems in sometrains while using supported catalyst systems in other trains. In otherembodiments, the catalyst systems in some reactor trains may comprisealuminoxane (for example, MAO) activator, while comprisingnon-coordinating anion activators in some other trains. In anotherembodiments, the catalyst systems in some reactor trains may compriseZiegler-Natta catalysts, while the catalyst systems in other reactortrains of the invention process may comprise metallocenes ornonmetallocene metal-centered, heteroaryl ligand catalyst compounds(where the metal is chosen from the Group 4, 5, 6, the lanthanideseries, or the actinide series of the Periodic Table of the Elements)activated by aluminoxane or non-coordinating anion activators or anycombinations thereof. While the number of different catalyst systemsdeployed in the invention processes can be any number, the use of nomore than five different catalysts and more particularly, no more thanthree different catalysts in any given reactor is advantageous foreconomic reasons. The deployment of no more than ten catalysts or thedeployment of no more than six catalysts in the reactor bank of thepolymerization process is advantageous for economic reasons. The one ormore catalysts deployed in the reactors may be homogeneously dissolvedin the fluid reaction medium or may form a heterogeneous solid phase inthe reactor. In one particular embodiment, the catalyst(s) is (are)homogeneously dissolved in the fluid reaction medium. When the catalystis present as a solid phase in the polymerization reactor, it may besupported or unsupported.

The process disclosed herein may use any combination of homogeneous andheterogeneous catalyst systems simultaneously present in one or more ofthe individual reactors of the polymerization reactor section, i.e., anyreactor of the polymerization section of the present invention maycontain one or more homogeneous catalyst systems and one or moreheterogeneous catalyst systems simultaneously. The process disclosedherein may also use any combination of homogeneous and heterogeneouscatalyst systems deployed in the polymerization reactor section. Thesecombinations comprise scenarios when some or all reactors use a singlecatalyst and scenarios when some or all reactors use more than onecatalyst. The one or more catalysts deployed in the process disclosedherein may be supported on particles, which either can be dispersed inthe fluid polymerization medium or may be contained in a stationarycatalyst bed. When the supported catalyst particles are dispersed in thefluid reaction medium, they may be left in the polymeric product or maybe separated from the product prior to its crystallization from thefluid reactor effluent in a separation step that is downstream of thepolymerization reactor section. If the catalyst particles are recovered,they may be either discarded or may be recycled with or withoutregeneration.

The catalyst may also be supported on structured supports, such as forexample, monoliths comprising straight or tortuous channels, reactorwalls, and internal tubing. When the catalysts are supported, operationmay take place on dispersed particles. When the catalyst is supported ondispersed particles, operations may take place without catalyst recoveryi.e., the catalyst is left in the polymeric product. In anotherembodiment, unsupported catalysts may be dissolved in the fluid reactionmedium.

Catalyst systems may be introduced into the reactor by any number ofmethods. For example, the catalyst may be introduced with themonomer-containing feed or separately. Also, the catalyst(s) may beintroduced through one or multiple ports to the reactor. If multipleports are used for introducing the catalyst, those ports may be placedat essentially the same or at different positions along the length ofthe reactor. If multiple ports are used for introducing the catalyst,the composition and the amount of catalyst feed through the individualports may be the same or different. Adjustment in the amounts and typesof catalyst through the different ports enables the modulation ofpolymer properties, such as for example, molecular weight distribution,composition, composition distribution, and crystallinity.

FIG. 24 is a plot of turnover frequency as a function of catalystconcentration in homogeneous supercritical propylene polymerization withMAO-activated (μ-dimethylsilyl)bis(2-methyl-4-phenylindenyl)zirconiumdichloride (Q-Zr-MAO) at 120-130° C. and 10 or 20 kpsi total pressure.The figure shows that turnover frequency independent of catalystconcentration suggesting first kinetic order for catalyst in homogeneoussupercritical propylene polymerization with MAO-activated(μ-dimethylsilyl)bis(2-methyl-4-phenylindenyl)zirconium dichloride(Q-Zr-MAO). Stated differently, the monomer conversion rate isproportional to the concentration of the metallocene component(expressed as Zr-concentration) of the catalyst system comprising the(μ-dimethylsilyl)bis(2-methyl-4-phenylindenyl)zirconium dichloridecatalyst precursor compound and the MAO activator (the latter employedin a 400:1 Al/Zr ratio).

Catalyst Compounds and Mixtures:

The processes described herein may use any polymerization catalystcapable of polymerizing the monomers disclosed herein if that catalystis sufficiently active under the polymerization conditions disclosedherein. Thus, Group-3-10 transition metals may form suitablepolymerization catalysts. A suitable olefin polymerization catalyst willbe able to coordinate to, or otherwise associate with, an alkenylunsaturation. Illustrative, but not limiting, olefin polymerizationcatalysts include Ziegler-Natta catalyst compounds, metallocene catalystcompounds, late transition metal catalyst compounds, and othernon-metallocene catalyst compounds.

Distinction should made between active catalysts, also referred to ascatalyst systems herein, and catalyst precursor compounds. Catalystsystems are active catalysts comprising one or more catalyst precursorcompounds, one or more catalyst activators, and optionally, one or moresupports. Catalytic activity is often expressed based on theconcentration of the catalyst precursor compounds without implying thatthe active catalyst is the precursor compound alone. It should beunderstood that the catalyst precursor is inactive without beingcontacted or being treated with a proper amount of activator. Similarly,the catalyst activator is inactive without combining it with a properamount of precursor compound. As will become clear from the followingdescription, some activators are very efficient and can be usedstoichiometrically, while some others are used in excess, and insometimes large excess, to achieve high catalytic activity as expressedbased on the concentration of the catalyst precursor compounds. Sincesome of these activators, for example methylaluminoxane (MAO), increasecatalytic activity as expressed based on the concentration of thecatalyst precursor compounds, they are sometimes referred to as“cocatalysts” in the technical literature of polymerization.

As disclosed herein, Ziegler-Natta catalysts are those referred to asfirst, second, third, fourth, and fifth generation catalysts in thePROPYLENE HANDBOOK, E. P. Moore, Jr., Ed., Hanser, New York, 1996.Metallocene catalysts in the same reference are described as sixthgeneration catalysts. One exemplary non-metallocene catalyst compoundcomprises nonmetallocene metal-centered, heteroaryl ligand catalystcompounds (where the metal is chosen from the Group 4, 5, 6, thelanthanide series, or the actinide series of the Periodic Table of theElements).

Just as in the case of metallocene catalysts, these nonmetallocenemetal-centered, heteroaryl ligand catalyst compounds are typically madefresh by mixing a catalyst precursor compound with one or moreactivators. Nonmetallocene metal-centered, heteroaryl ligand catalystcompounds are described in detail in PCT Patent Publications Nos. WO02/38628, WO 03/040095 (pages 21 to 51), WO 03/040201 (pages 31 to 65),WO 03/040233 (pages 23 to 52), WO 03/040442 (pages 21 to 54), WO2006/38628, and U.S. patent application Ser. No. 11/714,546, each ofwhich is herein incorporated by reference.

Particularly useful metallocene catalyst and non-metallocene catalystcompounds are those disclosed in paragraphs [0081] to [0111] of U.S.Ser. No. 10/667,585 and paragraphs [0173] to [0293] of U.S. Ser. No.11/177,004, the paragraphs of which are herein incorporated byreference.

An exemplary family of suitable catalysts for producing both the iPP andEP blend components is known in the art as bridged bisindenylmetallocenes. As described by many papers (see for example, W. Spalecket al., Organometallics, 13 (1994) 954, W. Spaleck et al., “NewIsotactic Polypropylenes via Metallocene Catalysts” in ZieglerCatalysts, Fink/Mulhaupt/Brintzinger, Eds., Springer, Berlin, 1995, andL. Resconi et al., J. Am Chem. Soc. 120 (1998) 2308). This family ofmetallocene catalysts can provide both high and low stereo regularityfor propylene incorporation depending on the substitution on thebisindenyl scaffold. For example, the unsubstituted parent (such as forexample, the Hf version, dimethyl (μ-dimethylsilyl)bis(indenyl)hafniumactivated by MAO or borate non-coordinating anion activators) mayprovide for low stereoregularity, and thus reduced crystallinity, whilesome substituted derivatives, particularly the 2,4-substituted versions(such as, for example, the Zr version, dimethyl(μ-dimethylsilyl)bis(2-methyl-4-naphthylindenyl)zirconium), afford highstereoregularity. The latter thus is particularly useful for producinghigh-crystallinity iPP blend components.

The processes disclosed herein can employ mixtures of catalyst compoundsto tailor the properties that are desired from the polymer. Mixedcatalyst systems prepared from more than one catalyst precursorcompounds can be employed in the in-line blending processes to alter orselect desired physical or molecular properties. For example, mixedcatalyst systems can control the molecular weight distribution ofisotactic polypropylene. when used with the invention processes or forthe invention polymers. In one embodiment of the processes disclosedherein, the polymerization reaction(s) may be conducted with two or morecatalyst precursor compounds at the same time or in series. Inparticular, two different catalyst precursor compounds can be activatedwith the same or different activators and introduced into thepolymerization system at the same or different times. These systems canalso, optionally, be used with diene incorporation to facilitate longchain branching using mixed catalyst systems and high levels of vinylterminated polymers.

As disclosed herein, two or more of the above catalyst precursorcompounds can be used together.

Activators and Activation Methods for Catalyst Compounds:

The catalyst precursor compounds described herein are combined withactivators for use as active catalysts herein.

An activator is defined as any combination of reagents that increasesthe rate at which a metal complex polymerizes unsaturated monomers, suchas olefins. An activator may also affect the molecular weight, degree ofbranching, comonomer content, or other properties of the polymer.

A. Aluminoxane and Aluminum Alkyl Activators:

In one form, one or more aluminoxanes are utilized as an activator inthe in-line blending processes disclosed herein. Alkyl aluminoxanes,sometimes called aluminoxanes in the art, are generally oligomericcompounds containing —Al(R)—O— subunits, where R is an alkyl group.Examples of aluminoxanes include methylaluminoxane (MAO), modifiedmethylaluminoxane (MMAO), ethylaluminoxane and isobutylaluminoxane.Alkylaluminoxanes and modified alkylaluminoxanes are suitable ascatalyst activators, particularly when the abstractable ligand is ahalide. Mixtures of different aluminoxanes and modified aluminoxanes mayalso be used. For further descriptions, see U.S. Pat. Nos. 4,665,208,4,952,540, 5,041,584, 5,091,352, 5,206,199, 5,204,419, 4,874,734,4,924,018, 4,908,463, 4,968,827, 5,329,032, 5,248,801, 5,235,081,5,157,137, 5,103,031 and European and PCT Patent Publication Nos. EP 0561 476 A1, EP 0 279 586 B1, EP 0 516 476 A, EP 0 594 218 A1 and WO94/10180, all of which are herein incorporated by reference in theirentirety.

When the activator is an aluminoxane (modified or unmodified), someembodiments select the maximum amount of activator at a 5000-fold molarexcess Al/M over the catalyst compound (per metal catalytic site). Theminimum activator-to-catalyst-compound is typically a 1:1 molar ratio.

B. Ionizing Activators:

It is contemplated to use an ionizing or stoichiometric activator,neutral or ionic, such as tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)boron, a trisperfluorophenyl borone metalloidprecursor or a trisperfluoronaphtyl borone metalloid precursor,polyhalogenated heteroborane anions (PCT patent publication no. WO98/43983), boric acid (U.S. Pat. No. 5,942,459) or combination thereofas an activator herein. Also contemplated for use herein are neutral orionic activators alone or in combination with aluminoxane or modifiedaluminoxane activators.

Examples of neutral stoichiometric activators include tri-substitutedboron, aluminum, gallium and indium or mixtures thereof. The threesubstituent groups are each independently selected from alkyls,alkenyls, halogen, substituted alkyls, aryls, arylhalides, alkoxy andhalides. The three groups are independently selected from halogen, monoor multicyclic (including halosubstituted) aryls, alkyls, and alkenylcompounds and mixtures thereof, particularly advantageous are alkenylgroups having 1 to 20 carbon atoms, alkyl groups having 1 to 20 carbonatoms, alkoxy groups having 1 to 20 carbon atoms and aryl groups having3 to 20 carbon atoms (including substituted aryls). Alternately, thethree groups are alkyls having 1 to 4 carbon groups, phenyl, naphthyl ormixtures thereof. Alternately, the three groups are halogenated,advantageously fluorinated, aryl groups. Alternately, the neutralstoichiometric activator is trisperfluorophenyl boron ortrisperfluoronapthyl boron.

Ionic stoichiometric activator compounds may contain an active proton,or some other cation associated with, but not coordinated to, or onlyloosely coordinated to, the remaining ion of the ionizing compound. Suchcompounds and the like are described in European patent publication Nos.EP-A-0 570 982, EP-A-0 520 732, EP-A-0 495 375, EP-B1-0 500 944, EP-A-0277 003 and EP-A-0 277 004, and U.S. Pat. Nos. 5,153,157, 5,198,401,5,066,741, 5,206,197, 5,241,025, 5,384,299 and 5,502,124 and U.S. patentapplication Ser. No. 08/285,380, filed Aug. 3, 1994, all of which areherein fully incorporated by reference.

C. Non-Ionizing Activators:

Activators are typically strong Lewis-acids which may play either therole of ionizing or non-ionizing activator. Activators previouslydescribed as ionizing activators may also be used as non-ionizingactivators.

Abstraction of formal neutral ligand may be achieved with Lewis-acidsthat display an affinity for the formal neutral ligand. TheseLewis-acids are typically unsaturated or weakly coordinated. Examples ofnon-ionizing activators include R¹⁰(R¹¹)₃, where R¹⁰ is a group 13element and R¹¹ is a hydrogen, a hydrocarbyl, a substituted hydrocarbyl,or a functional group. Typically, R¹¹ is an arene or a perfluorinatedarene. Non-ionizing activators also include weakly coordinatedtransition metal compounds such as low valent olefin complexes.

Non-limiting examples of non-ionizing activators include BMe₃, BEt₃,B(iBu)₃, BPh₃, B(C₆F₅)₃, AlMe₃, AlEt₃, Al(iBu)₃, AlPh₃, B(C₆F₅)₃,aluminoxane, CuCl, Ni(1,5-cyclooctadiene)₂.

Additional neutral Lewis-acids are known in the art and will be suitablefor abstracting formal neutral ligand. See in particular the reviewarticle by E. Y.-X. Chen and T. J. Marks, “Cocatalysts forMetal-Catalyzed Olefin Polymerization: Activators, Activation Processes,and Structure-Activity Relationships”, Chem. Rev., 100, 1391-1434(2000).

Suitable non-ionizing activators include R¹⁰(R¹¹)₃, where R¹⁰ is a group13 element and R¹¹ is a hydrogen, a hydrocarbyl, a substitutedhydrocarbyl, or a functional group. Typically, R¹¹ is an arene or aperfluorinated arene.

Other non-ionizing activators include B(R¹²)₃, where R¹² is an arene ora perfluorinated arene. Alternately, non-ionizing activators includeB(C₆H₅)₃ and B(C₆F₅)₃. Another non-ionizing activator is B(C₆F₅)₃.Alternately, activators include ionizing and non-ionizing activatorsbased on perfluoroaryl borane and perfluoroaryl borates such as PhNMe₂H⁺B(C₆F₅)₄ ⁻, (C₆H₅)₃C⁺ B(C₆F₅)₄ ⁻, and B(C₆F₅)₃.

Additional activators that may be used with the catalyst compoundsdisclosed herein include those described in PCT patent publication No.WO 03/064433A1, which is incorporated by reference herein in itsentirety.

Additional useful activators for use in the processes disclosed hereininclude clays that have been treated with acids (such as H₂SO₄) and thencombined with metal alkyls (such as triethylaluminum) as described inU.S. Pat. No. 6,531,552 and EP Patent No. 1 160 261 A1, which areincorporated by reference herein.

Activators also may be supports and include ion-exchange layeredsilicate having an acid site of at most −8.2 pKa, the amount of the acidsite is equivalent to at least 0.05 mmol/g of 2,6-dimethylpyridineconsumed for neutralization. Non-limiting examples include chemicallytreated smectite group silicates, acid-treated smectite group silicates.Additional examples of the ion-exchange layered silicate include layeredsilicates having a 1:1 type structure or a 2:1 type structure asdescribed in “Clay Minerals (Nendo Kobutsu Gaku)” written by HaruoShiramizu (published by Asakura Shoten in 1995).

Examples of an ion-exchange layered silicate comprising the 1:1 layer asthe main constituting layer include kaolin group silicates such asdickite, nacrite, kaolinite, metahalloysite, halloysite or the like, andserpentine group silicates such as chrysotile, lizaldite, antigorite orthe like. Additional non-limiting examples of the ion-exchange layeredsilicate include ion-exchange layered silicates comprising the 2:2 layeras the main constituting layer include smectite group silicates such asmontmorillonite, beidellite, nontronite, saponite, hectorite,stephensite or the like, vermiculite group silicates such as vermiculiteor the like, mica group silicates such as mica, illite, sericite,glauconite or the like, and attapulgite, sepiolite, palygorskite,bentonite, pyrophyllite, talc, chlorites and the like. The clays arecontacted with an acid, a salt, an alkali, an oxidizing agent, areducing agent or a treating agent containing a compound intercalatablebetween layers of an ion-exchange layered silicate. The intercalationmeans to introduce other material between layers of a layered material,and the material to be introduced is called as a guest compound. Amongthese treatments, acid treatment or salt treatment is particularlyadvantageous. The treated clay may then be contacted with an activatorcompound, such as TEAL, and the catalyst compound to polymerize olefins.

In another form, the polymerization systems comprise less than 5 wt %polar species, or less than 4 wt %, or less than 3 wt %, or less than 2wt %, or less than 1 wt %, or less than 1000 ppm, or less than 750 ppm,or less than 500 ppm, or less than 250 ppm, or less than 100 ppm, orless than 50 ppm, or less than 10 ppm. Polar species include oxygencontaining compounds (except for alumoxanes) such as alcohols, oxygen,ketones, aldehydes, acids, esters and ethers.

In yet another form, the polymerization systems comprise less than 5 wt% trimethylaluminum and/or triethylaluminum, or less than 4 wt %, orless than 3 wt %, or less than 2 wt %, or less than 1 wt %, or less than1000 ppm, or less than 750 ppm, or less than 500 ppm, or less than 250ppm, or less than 100 ppm, or less than 50 ppm, or less than 10 ppm.

In still yet another form, the polymerization systems comprisemethylaluminoxane and less than 5 wt % trimethylaluminum and ortriethylaluminum, or less than 4 wt %, or less than 3 wt %, or less than2 wt %, or less than 1 wt %, or less than 1000 ppm, or less than 750ppm, or less than 500 ppm, or less than 250 ppm, or less than 100 ppm,or less than 50 ppm, or less than 10 ppm.

The in-line blending processes disclosed herein may use finely divided,supported catalysts to prepare propylene/1-hexene copolymers withgreater than 1.0 mole % 1-hexene. In addition to finely dividedsupports, in-line blending processes disclosed herein may use fumedsilica supports in which the support particle diameter may range from200 angstroms to 1500 angstroms, small enough to form a colloid withreaction media.

Catalyst Supports:

In another form, the catalyst compositions of fluid phase in-lineblending processes disclosed herein may include a support material orcarrier. For example, the one or more catalyst components and/or one ormore activators may be deposited on, contacted with, vaporized with,bonded to, or incorporated within, adsorbed or absorbed in, or on, oneor more supports or carriers.

The support material may be any of the conventional support materials.In one form, the supported material may be a porous support material,for example, talc, inorganic oxides and inorganic chlorides. Othersupport materials may include resinous support materials such aspolystyrene, functionalized or crosslinked organic supports, such aspolystyrene divinyl benzene polyolefins or polymeric compounds,zeolites, clays, or any other organic or inorganic support material andthe like, or mixtures thereof.

Useful support materials are inorganic oxides that include those Group2, 3, 4, 5, 13 or 14 metal oxides. In one form, the supports includesilica, which may or may not be dehydrated, fumed silica, alumina (PCTpatent publication No. WO 99/60033), silica-alumina and mixturesthereof. Other useful supports include magnesia, titania, zirconia,magnesium chloride (U.S. Pat. No. 5,965,477), montmorillonite (EuropeanPatent No. EP-B1 0 511 665), phyllosilicate, zeolites, talc, clays (U.S.Pat. No. 6,034,187) and the like. Also, combinations of these supportmaterials may be used, for example, silica-chromium, silica-alumina,silica-titania and the like. Additional support materials may includethose porous acrylic polymers described in European Patent No. EP 0 767184 B 1, which is incorporated herein by reference. Other supportmaterials include nanocomposites as described in PCT WO 99/47598,aerogels as described in WO 99/48605, spherulites as described in U.S.Pat. No. 5,972,510 and polymeric beads as described in WO 99/50311,which are all herein incorporated by reference.

The support material, for example an inorganic oxide, has a surface areain the range of from about 10 to about 700 m²/g, pore volume in therange of from about 0 to about 4.0 cc/g and average particle size in therange of from about 0.02 to about 50 μm. Alternatively, the surface areaof the support material is in the range of from about 50 to about 500m²/g, pore volume of from about 0 to about 3.5 cc/g and average particlesize of from about 0.02 to about 20 μm. In another form, the surfacearea of the support material is in the range is from about 100 to about400 m²/g, pore volume from about 0 to about 3.0 cc/g and averageparticle size is from about 0.02 to about 10 μm.

Non-porous supports may also be used as supports in the processesdescribed herein. For example, in a one embodiment the nonporous, fumedsilica supports described in U.S. Pat. No. 6,590,055 may be used and isincorporated by reference herein.

While supported catalysts may be used in the disclosed in-line blendingprocesses for making iPP-EP blends, unsupported catalysts are moreadvantageous due to their better handling properties under homogeneouspolymerization conditions.

Isotactic PP & EP Copolymer Polymerization Scavengers

Compounds that destroy impurities are referred to as scavengers by oneskilled in the art of polymerization. Impurities may harm catalysts byreducing their activity. Scavengers may be optionally fed to thereactor(s) of the in-line blending process disclosed herein. Catalyticactivity may be defined many different ways. For example, catalyticactivity can be expressed as turnover frequency, i.e., the number ofmoles of monomers converted to the product in a unit time by one mole ofcatalyst precursor employed in preparing the active catalyst system. Fora given reactor operating at the same residence time, catalytic activitymay also be measured in terms of catalyst productivity, customarilyexpressed as the weight of polymer made by a unit weight of catalystprecursor with or without the weight of the activator.

The scavengers for use in the processes disclosed herein may bedifferent chemical compound(s) from the catalyst activator. Non-limitingexemplary scavengers include diethyl zinc, and alkyl aluminum compounds,such as trimethyl aluminum, triethyl aluminum, tri-isobutyl aluminum,and trioctyl aluminum. The scavenger may also be the same as thecatalyst activator and is generally applied in excess of what is neededto fully activate the catalyst. These scavengers include, but are notlimited to, aluminoxanes, such as methyl aluminoxane. The scavenger mayalso be introduced to the reactor with the monomer feed or with anyother feed stream. In one particular embodiment, the scavenger isintroduced with the monomer-containing feed. The scavenger may behomogeneously dissolved in the polymerization reaction medium or mayform a separate solid phase. In one particular embodiment, scavengersare dissolved in the polymerization medium.

Isotactic PP and EP Copolymer Polymerization Reactor Configuration

The polymerization processes of the fluid phase in-line process for iPPand EP copolymer blending disclosed herein may be carried out in two ormore reactors making the iPP and EP copolymer for downstream blending.In one embodiment, PP homopolymer and EP copolymer blends are made byusing two reactor trains in a parallel configuration. In another form,the PP homopolymer and EP copolymer blends are made by using three, orfour, or five, or six reactor trains in a parallel configuration.

As previously described, the in-line blending iPP and EP copolymer blendcomponents are produced in a reactor bank composed of at least twoparallel reactor trains. A reactor train of the parallel reactor bankmay include one or more reactors that may be configured in seriesconfiguration. The number of parallel reactors trains or branches in aparallel bank may be any number, but for practical reasons, is generallylimited to less than ten, alternatively not more than six parallelreactor trains, alternatively not more than five or not more than fourreactor trains, alternatively not more than three parallel reactortrains, and alternatively not more than two parallel reactor trains. Thenumber of series cascade reactors constituting a given reactor train orbranch of a parallel configuration may be any number, but for practicalreasons, is generally limited to not more than ten reactors in series,alternatively not more than six reactors in series, alternatively notmore than three reactors in series, and alternatively not more than tworeactors in series.

In one embodiment, the polymer-containing effluents from two or morereactor trains configured in a parallel configuration are combinedyielding a polymer blend comprising the polymeric products of theindividual reactors without first recovering the polymeric products ofthe individual reactors in solid forms. The two or more reactor trainsconstituting the parallel configuration generally include a singlereactor, or alternatively, two or more reactors in series.

The reactors of the polymerization system for the fluid phase in-lineprocess for iPP and EP copolymer blending disclosed herein may bestirred or unstirred. When a reactor train comprises two or morereactors, the members of the reactor train are not necessarilyconstructed the same way, for example, the individual members of areactor train may be stirred, unstirred, or a combination thereof. Theindividual reactors may also be of equal or different size. The same istrue for the reactors in the entire reactor bank. The optimal reactorconfiguration and sizes may be determined by standard engineeringtechniques known to those skilled in the art of chemical engineering.

Any type of polymerization reactor may be deployed in the fluid phasein-line process for blending disclosed herein. The optimal reactordesign may be determined by standard engineering techniques known tothose skilled in the art of chemical engineering. Non-limiting exemplaryreactor designs include stirred tank with or without an external loop,tubular reactor, and loop reactor. The reactors may operateadiabatically or may be cooled. The cooling may be achieved within thereactor, or through the reactor jacket, or dedicated heat exchange loopsmay be applied.

Isotactic PP and EP Copolymer Polymerization Reactors

The fluid phase in-line process for iPP and EP copolymer blendingdisclosed herein relates to processes to polymerize isotacticpolypropylene and EP copolymer comprising contacting propylene, ethyleneand optional one or more C₄ or higher olefins with suitable catalystcompounds and activators in a fluid reaction medium comprising one ortwo fluid phases in each parallel reactor. The polymerization system forat least one parallel reactor train producing either the iPP or EPcopolymer is in its supercritical state. Catalyst compound and activatormay be delivered as a solution or slurry, either separately to thereactor, mixed in-line just prior to the reactor, or mixed and pumped asan activated solution or slurry to the reactor. For a given reactortrain of the parallel configuration, polymerizations may be carried outin either single reactor operation, in which monomer, comonomers,catalyst(s)/activator(s), scavenger(s), and optional solvent(s) areadded continuously to a single reactor or in series reactor operation,in which the above components are added to two or more reactorsconnected in series. The catalyst components may be added to the firstreactor in the series. The catalyst component may also be added to eachreactor in the series reactor train. The fresh catalyst feed if added tomore than one reactor in the series train may be the same or differentto each reactor and their feed rates may be the same or different.

Polymerization processes of the fluid phase in-line process for blendingdisclosed herein also comprehend high-pressure reactors where thereactor is substantially unreactive with the polymerization reactioncomponents and is able to withstand the high pressures and temperaturesthat occur during the polymerization reaction. Withstanding these highpressures and temperatures may allow the reactor to maintain the fluidreaction medium in its supercritical condition. Suitable reaction vesseldesigns include those necessary to maintain supercritical or otherhigh-pressure ethylene polymerization reactions. Non-limiting exemplaryreactors include autoclave, pump-around loop or autoclave, tubular, andautoclave/tubular reactors.

The polymerization processes of the fluid phase in-line process forblending disclosed herein may operate efficiently in autoclave (alsoreferred to as stirred tank) and tubular reactors. Autoclave reactorsmay be operated in either a batch or continuous mode, although thecontinuous mode is advantageous. Tubular reactors always operate incontinuous mode. Typically, autoclave reactors have length-to-diameterratios of 1:1 to 20:1 and are fitted with a high-speed (up to 2000 RPM)multiblade stirrer and baffles arranged for optimal mixing. Commercialautoclave pressures are typically greater than 5 MPa with a maximum oftypically less than 260 MPa. The maximum pressure of commercial.autoclaves, however, may become higher with advances in mechanical andmaterial science technologies.

When the autoclave has a low length-to-diameter ratio (such as less thanfour), the feed streams may be injected at one position along the lengthof the reactor. Reactors with large diameters may have multipleinjection ports at nearly the same or different positions along thelength of the reactor. When they are positioned at the same length ofthe reactor, the injection ports are radially distributed to allow forfaster intermixing of the feed components with the reactor content. Inthe case of stirred tank reactors, the separate introduction of thecatalyst and monomer(s) may be advantageous in preventing the possibleformation of hot spots in the unstirred feed zone between the mixingpoint and the stirred zone of the reactor. Injections at two or morepositions along the length of the reactor is also possible and may beadvantageous. In one exemplary embodiment, in reactors where thelength-to-diameter ratio is from 4 to 20, the reactor may contain up tosix different injection positions along the reactor length with multipleports at some or each of the lengths.

Additionally, in the larger autoclaves, one or more lateral mixingdevices may support the high-speed stirrer. These mixing devices canalso divide the autoclave into two or more zones. Mixing blades on thestirrer may differ from zone to zone to allow for a different degree ofplug flow and back mixing, largely independently, in the separate zones.Two or more autoclaves with one or more zones may connect in a seriesreactor cascade to increase residence time or to tailor polymerstructure in a reactor train producing a polymer blending component. Aspreviously described, a series reactor cascade or configuration consistsof two or more reactors connected in series, in which the effluent of atleast one upstream reactor is fed to the next reactor downstream in thecascade. Besides the effluent of the upstream reactor(s), the feed ofany reactor in the series reactor cascade of a reactor train can beaugmented with any combination of additional monomer, catalyst, orsolvent fresh or recycled feed streams. Therefore, it should beunderstood that the iPP or EP copolymer blending component leaving areactor train of the process disclosed herein may itself be a blend ofthe same polymer with increased molecular weight and/or compositionaldispersion.

Tubular reactors may also be used in the fluid phase in-line process forblending disclosed herein and more particularly tubular reactors capableof operating up to about 350 MPa. Tubular reactors are fitted withexternal cooling and one or more injection points along the (tubular)reaction zone. As in autoclaves, these injection points serve as entrypoints for monomers (such as propylene), one or more comonomer,catalyst, or mixtures of these. In tubular reactors, external coolingoften allows for increased monomer conversion relative to an autoclave,where the low surface-to-volume ratio hinders any significant heatremoval. Tubular reactors have a special outlet valve that can send apressure shockwave backward along the tube. The shockwave helps dislodgeany polymer residue that has formed on reactor walls during operation.Alternatively, tubular reactors may be fabricated with smooth,unpolished internal surfaces to address wall deposits. Tubular reactorsgenerally may operate at pressures of up to 360 MPa, may have lengths of100-2000 meters or 100-4000 meters, and may have internal diameters ofless than 12.5 cm. Typically, tubular reactors have length-to-diameterratios of 10:1 to 50,000:1 and include up to 10 different injectionpositions along its length.

Reactor trains that pair autoclaves with tubular reactors are alsocontemplated within the scope of the fluid phase in-line process forblending disclosed herein. In this reactor system, the autoclavetypically precedes the tubular reactor or the two types of reactors formseparate trains of a parallel reactor configuration. Such reactorsystems may have injection of additional catalyst and/or feed componentsat several points in the autoclave, and more particularly along the tubelength. In both autoclaves and tubular reactors, at injection, feeds aretypically cooled to near ambient temperature or below to provide maximumcooling and thus maximum polymer production within the limits of maximumoperating temperature. In autoclave operation, a preheater may operateat startup, but not after the reaction reaches steady state if the firstmixing zone has some back-mixing characteristics. In tubular reactors,the first section of double-jacketed tubing may be heated (especially atstart ups) rather than cooled and may operate continuously. Awell-designed tubular reactor is characterized by plug flow wherein plugflow refers to a flow pattern with minimal radial flow rate differences.In both multizone autoclaves and tubular reactors, catalyst can not onlybe injected at the inlet, but also optionally at one or more pointsalong the reactor. The catalyst feeds injected at the inlet and otherinjection points can be the same or different in terms of content,density, and concentration. Catalyst feed selection allows polymerdesign tailoring within a given reactor or reactor train and/ormaintaining the desired productivity profile along the reactor length.

At the reactor outlet valve, the pressure drops to begin the separationof polymer and unreacted monomer, co-monomers, solvents and inerts, suchas for example ethane, propane, hexane, and toluene. More particularly,at the reactor outlet valve, the pressure drops to levels below thatwhich critical phase separation allowing for a polymer-rich phase and apolymer-lean phase in the downstream separation vessel. Typically,conditions remain above the polymer product's crystallizationtemperature. The autoclave or tubular reactor effluent may bedepressurized on entering the downstream high-pressure separator (HPS oralso referred to as a separator, separator vessel, separation vessel,separator/blender vessel, or separation/blending vessel).

As will be subsequently described in detail, the temperature in theseparation vessel is maintained above the solid-fluid phase separationtemperature, but the pressure may be below the critical point. Thepressure need only be high enough such that the monomer may condenseupon contacting standard cooling water. The liquid recycle stream maythen be recycled to the reactor with a liquid pumping system instead ofthe hyper-compressors required for polyethylene units. The relativelylow pressure in separator reduces the monomer concentration in theliquid polymer phase which results in a lower polymerization rate. Thepolymerization rate may be low enough to operate the system withoutadding a catalyst poison or “killer”. If a catalyst killer is required(e.g., to prevent reactions in the high pressure recycle) then provisionmust be made to remove any potential catalyst poisons from the recycledpolymer rich monomer stream for example, by the use of fixed bedadsorbents or by scavenging with an aluminum alkyl.

In an alternative embodiment, the HPS may be operated over the criticalpressure of the monomer or monomer blend but within the densefluid-fluid two phase region, which may be advantageous if the polymeris to be produced with a revamped high-pressure polyethylene (HPPE)plant. The recycled HPS overhead is cooled and dewaxed before beingreturned to the suction of the secondary compressor, which is typical ofHPPE plant operation. The polymer from this intermediate orhigh-pressure vessel then passes through another pressure reduction stepto a low pressure separator. The temperature of this vessel ismaintained above the polymer melting point so that the polymer from thisvessel can be fed as a liquid directly to an extruder or static mixer.The pressure in this vessel is kept low by using a compressor to recoverthe unreacted monomers, etc. to the condenser and pumping systemreferenced above.

In addition to autoclave reactors, tubular reactors, or a combination ofthese reactors, loop-type reactors may be utilized in the fluid phasein-line process for blending disclosed herein. In this reactor type,monomer enters and polymer exits continuously at different points alongthe loop, while an in-line pump continuously circulates the contents(reaction liquid). The feed/product takeoff rates control the totalaverage residence time. A cooling jacket removes reaction heat from theloop. Typically feed inlet temperatures are near to or below ambienttemperatures to provide cooling to the exothermic reaction in thereactor operating above the crystallization temperature of the polymerproduct. The loop reactor may have a diameter of 41 to 61 cm and alength of 100 to 200 meters and may operate at pressures of 25 to 30MPa. In addition, an in-line pump may continuously circulate thepolymerization system through the loop reactor.

The polymerization processes of the fluid phase in-line process forblending iPP and EP copolymer components disclosed herein may haveresidence times in the reactors as short as 0.5 seconds and as long asseveral hours, alternatively from 1 sec to 120 min, alternatively from 1second to 60 minutes, alternatively from 5 seconds to 30 minutes,alternatively from 30 seconds to 30 minutes, alternatively from 1 minuteto 60 minutes, and alternatively from 1 minute to 30 minutes. Moreparticularly, the residence time may be selected from 10, or 30, or 45,or 50, seconds, or 1, or 5, or 10, or 15, or 20, or 25, or 30 or 60 or120 minutes. Maximum residence times may be selected from 1, or 5, or10, or 15, or 30, or 45, or 60, or 120 minutes.

The monomer-to-polymer conversion rate (also referred to as theconversion rate) is calculated by dividing the total quantity of polymerthat is collected during the reaction time by the amount of monomeradded to the reaction. Lower conversions may be advantageous to limitviscosity although increase the cost of monomer recycle. The optimumtotal monomer conversion thus will depend on reactor design, productslate, process configuration, etc., and can be determined by standardengineering techniques. Total monomer conversion during a single passthrough any individual reactor of the fluid phase in-line process forblending disclosed herein may be up to 90%, or below 80%, or below 60%or 3 to 80%, or 5 to 80%, or 10 to 80%, or 15 to 80%, or 20 to 80%, or25 to 60%, or 3 to 60%, or 5 to 60%, or 10 to 60%, or 15 to 60%, or 20to 60%, or 10 to 50%, or 5 to 40%, or 10 to 40%, or 40 to 50%, or 15 to40%, or 20 to 40%, or 30 to 40% or greater than 5%, or greater than 10%.In one embodiment, when producing isotactic polypropylene and long-chainbranching (LCB) of the polypropylene is desired (g′≦0.97 based on GPC-3Dand using an isotactic polypropylene standard), single pass conversionsmay be above 30% and alternatively single-pass conversions may be above40%. In another embodiment, when isotactic polypropylene essentiallyfree of LCB is desired (0.97<g′<1.05), single-pass conversions may benot higher than 30% and alternatively single-pass-conversions may be nothigher than 25%. To limit the cost of monomer separation and recycling,single-pass conversions may be above 3%, or above 5%, or above 10%. Itshould be understood that the above exemplary conversion values reflecttotal monomer conversion, i.e., the conversion obtained by dividing thecombined conversion rate of all monomers by the total monomer feed rate.When monomer blends are used, the conversion of the more reactivemonomer component(s) will always be higher than that of the lessreactive monomer(s). Therefore, the conversion of the more reactivemonomer component(s) can be substantially higher than the totalconversion values given above, and can be essentially complete,approaching 100%.

Product Separation and Downstream Processing

The iPP and EP copolymer reactor effluents of the processes disclosedherein are depressurized to a pressure significantly below the cloudpoint pressure. This allows separation of a polymer-rich phase forfurther purification and a monomer-rich phase for optional separationand recycle compression back to the reactor(s). The reactor effluentsmay be optionally heated before pressure let down to avoid theseparation of a solid polymer phase, which causes fouling of theseparators and associated reduced-pressure lines. The separation of thepolymer-rich phase and the monomer-rich phase in the processes disclosedherein is carried out in a vessel known as a high-pressure separator(also referred to as an HPS, separator, separator vessel, or separationvessel). The high-pressure separator located after the mixing point ofthe polymer-containing product streams of all reactor trains of theparallel reactor bank is also referred to as, separator-blender,separator-blender vessel, or separation-blending vessel recognizing itsdual function of blending the said polymer-containing product streamswhile also separating a monomer-rich phase from a polymer-rich phase,the latter of which comprises the polymer blend of the in-line blendingprocesses disclosed herein.

In certain embodiments, single-stream high-pressure separators employedto partially recover the monomer(s) and optional solvent(s) from theeffluent of a single reactor train before sending the polymer-enrichedstream to the downstream separator-blender. In such embodiments, theseparator-blender blends one or more polymer-enriched stream with one ormore unreduced reactor train effluent to yield a monomer-rich phase anda polymer-rich phase, the latter of which comprises the polymer blend ofthe in-line blending process disclosed herein. In another embodiment,the single-stream high-pressure separator placed upstream of theseparator-blender also functions as a buffer vessel (separator-buffervessel) by allowing the fluid level of the polymer-enriched phase varyin the separator-buffer vessel. Such buffering enables a more precisecontrol of the blend ratios by compensating for the momentaryfluctuations in the production rates in the individual reactor trains ofthe in-line blending process disclosed herein.

The polymer rich phase of the separator-blender may then be transferredto one or more low-pressure separators (LPS also referred to as alow-pressure separation vessel) running at just above atmosphericpressure for a simple flash of light components, reactants and oligomersthereof, for producing a low volatile-containing polymer melt enteringthe finishing extruder or optional static mixer. The one or morelow-pressure separators are distinguished from the one or morehigh-pressure separators in generally operating at lower pressuresrelative to the high-pressure separators. The one or more low-pressureseparators also are located downstream of the one or more high-pressureseparators including the separator-blender. Moreover, the one or morelow-pressure separators may function to separate light from heavycomponents comprising the polymer blend of the in-line blending processdisclosed herein, whereas the one or more high-pressure separators mayfunction to separate light from heavy components upstream of thelow-pressure separator (i.e. monomer-rich phase from polymer-rich phase)and may function to blend the polymer-rich phases from two or moreparallel reactor trains or may function as buffers. As previouslystated, a high-pressure separator may be alternatively referred toherein as an HPS, separator, separator vessel, separation vessel,separator-blender vessel, or separation-blending vessel, orseparator-blender. The use of the term “pressure” in conjunction withlow-pressure separator and high-pressure separator is not meant toidentify the absolute pressure levels at which these separators operateat, but is merely intended to given the relative difference in pressureat which these separators operate. Generally, separators locateddownstream in the in-line blending processes disclosed herein operate atlower pressure relative to separators located upstream.

In one embodiment of the fluid phase in-line process for blending iPPand EP copolymer blend components disclosed herein, polymerization isconducted in two or more reactors of a type described herein above underagitation and above the cloud point for the polymerization system. Then,the polymer-monomer mixtures are transferred into a high-pressureseparation-blending vessel, where the pressure is allowed to drop belowthe cloud point. This advantageously results in the denser, polymer-richphase separating from the lighter monomer-rich phase. As may beappreciated by those skilled in the art, it may optionally be necessaryto increase the temperature before or in the high-pressure separationvessel to prevent the formation of a solid polymer phase as the polymerbecomes more concentrated. The monomer-rich phase is then separated andrecycled to the reactors while the polymer-rich phase is fed to acoupled devolatilizer—such as a LIST dryer (DTB) or devolatizingextruder.

The recycle runs through a separator, where the pressure depends on thepressure-temperature relationship existing within the reactor. Forexample, supercritical propylene polymerization can be carried out underagitation in the single-phase region in the reactor at 40 to 200 MPa and95 to 180° C. (see FIG. 18). The product mixture can be discharged intoa separator vessel, where the pressure is dropped to a level of 25 MPaor lower, in which case, the mixture is below its cloud point, while themonomer has not yet flashed off (again, see FIG. 18). Under suchconditions, it would be expected from Radosz et al., Ind. Eng. Chem.Res. 1997, 36, 5520-5525 and Loos et al., Fluid Phase Equil. 158-160,1999, 835-846 that the monomer-rich phase would comprise less than about0.1 wt % of low molecular weight polymer and have a density ofapproximately 0.3 to 0.6 g/mL (see FIG. 19). The polymer-rich phasewould be expected to have a density of approximately 0.5 to 0.8 g/mL.

Assuming that the pressure is dropped rapidly enough, for example,greater than or equal to about 6 MPa/sec, the phases will separaterapidly, permitting the recycle of the monomer-rich phase as a liquid,without the issue of having the monomer-rich phase return to the gasphase. As may be appreciated by those skilled in the art, thiseliminates the need for the energy-intensive compression andcondensation steps.

The polymer-rich phase is sent directly to a coupled devolatilizer.Suitable devolatilizers may be obtained, for example, from LIST USAInc., of Charlotte, N.C. The devolatilization is a separation process toseparate remaining volatiles from the final polymer, eliminating theneed for steam stripping. Working under low vacuum, the polymer solutionflashes into the devolatilizer, exits the unit and is then transferredon for further processing, such as pelletization.

Any low or very low molecular weight polymer present in the monomer-richphase to be recycled may optionally be removed through “knock-out” pots,standard hardware in reactors systems, or left in the return streamdepending upon product requirements and the steady-state concentrationof the low molecular weight polymer fraction in the product.

In solution reactor processes, present practices employed by thoseskilled in the art typically effect separation by flashing monomer andsolvent or accessing the high-temperature cloud point.

In another form, polymerization is conducted at conditions below thecloud point, with the polymer-monomer mixture transported to agravimetric separation vessel, where the pressure could be furtherlowered if desired to enhance phase separation of the polymer-rich andmonomer-rich phases. In either of the forms herein described, themonomer, for example, propylene, is recycled while staying in arelatively high density, liquid-like (supercritical or bulk liquid)state. Once again, one or more knock-out pots may be employed to aid inthe removal of low molecular weight polymer from the recycle stream.

As may be appreciated, there are possible and optimal operating regimesfor reactors and for the gravity (lower critical solution temperature(LCST)) separator. Referring now to FIG. 20, for reactors operating in asingle liquid phase regime, a possible region for operation is justabove the LCST and vapor pressure (VP) curves. The optimal region (shownwithin the shaded oval) for operation occurs at temperatures just abovethe lower critical end point (LCEP) and at pressures slightly above theLCST curve.

Referring now to FIG. 21, for reactors operating within a two-phasefluid-fluid regime, the possible region for operation occurs basicallyanywhere below the LCST curve. The optimal region (again, shown withinthe shaded oval) occurs just below the LCST and above the VP curve,although, as may be appreciated, many factors could have a bearing onwhat actually is optimal, such as the final properties of the desiredproduct. As recognized by those skilled in the art, the two-phaseliquid-liquid regime is the economically advantageous method ifpolypropylene is to be produced with a revamped HPPE plant.

Referring now to FIG. 22, for the case where polymerization is conductedat conditions below the cloud point and the polymer-monomer mixturetransported to a gravimetric LCST separator, the possible region ofoperation is anywhere below the LCST curve and above the VP curve. Theoptimal region (again, shown within the shaded oval) occurs within thatportion that is below the spinodal, but not too low in pressure, asshown. Operating in this regime assures that the energy use isoptimized. It is also desirable to avoid operation in the region betweenthe LCST and spinodal curves in order to obtain good gravity settlingperformance. Moreover, it is desirable that the separation is effectedat sufficiently high temperatures, so that crystallization does notoccur in the polymer-rich phase. This may require that the temperatureof the mixture in the separator be higher than the temperature in thereactor(s).

Advantageously, the liquid monomer-rich recycle stream can be recycledto the reactor using a liquid pumping system instead of ahyper-compressor, required for conventional polyethylene units.

Isotactic PP and EP Copolymer Polymerization Catalyst Killing

The use of the processes disclosed herein and the relatively lowpressure in the separator vessel greatly reduces the monomerconcentration in the liquid polymer-rich phase, which, in turn, resultsin a much lower polymerization rate. This polymerization rate may be lowenough to operate this system without adding a catalyst poison or“killer”. If no killing compounds are added then the killer removal stepmay be eliminated.

If a catalyst killer is required, then provision must be made to removeany potential catalyst poisons from the recycled monomer-rich stream(e.g. by the use of fixed bed adsorbents or by scavenging with analuminum alkyl). The catalyst activity may be killed by addition of apolar species. Non-limiting exemplary catalyst killing agents includewater, alcohols (such as methanol and ethanol), sodium/calcium stearate,CO, and combinations thereof. The choice and quantity of killing agentwill depend on the requirements for clean up of the recycle propyleneand comonomers as well as the product properties, if the killing agenthas low volatility. The catalyst killing agent may be introduced intothe reactor effluent stream after the pressure letdown valve, but beforethe HPS. The choice and quantity of killing agent may depend on therequirements for clean up of the recycle propylene and comonomers aswell as the product properties, if the killing agent has low volatility.

Polymer Additives

The in-line iPP and EP copolymer blends produced by the processdisclosed herein may be also blended with other polymers and additivesusing the in-line blending process for other polymers and additivesdepicted in FIG. 7, in an extrusion process downstream of in-linepolymerization/separation/blending processes disclosed herein, orblended in an off-line compounding process.

Tackifiers may also be blended either in-line by the processes disclosedherein (see FIG. 7), in-line via an extrusion process downstream ofin-line polymerization/separation/blending processes disclosed herein,or in an off-line compounding process. Examples of useful tackifiersinclude, but are not limited to, aliphatic hydrocarbon resins, aromaticmodified aliphatic hydrocarbon resins, hydrogenated polycyclopentadieneresins, polycyclopentadiene resins, gum rosins, gum rosin esters, woodrosins, wood rosin esters, tall oil rosins, tall oil rosin esters,polyterpenes, aromatic modified polyterpenes, terpene phenolics,aromatic modified hydrogenated polycyclopentadiene resins, hydrogenatedaliphatic resin, hydrogenated aliphatic aromatic resins, hydrogenatedterpenes and modified terpenes, and hydrogenated rosin esters. In someembodiments the tackifier is hydrogenated. In other embodiments thetackifier is non-polar. Non-polar tackifiers are substantially free ofmonomers having polar groups. The polar groups are generally notpresent; however, if present, they are not present at more that 5 wt %,or not more that 2 wt %, or no more than 0.5 wt %. In some embodiments,the tackifier has a softening point (Ring and Ball, as measured by ASTME-28) of 80° C. to 140° C., or 100° C. to 130° C. In some embodimentsthe tackifier is functionalized. By functionalized is meant that thehydrocarbon resin has been contacted with an unsaturated acid oranhydride. Useful unsaturated acids or anhydrides include anyunsaturated organic compound containing at least one double bond and atleast one carbonyl group. Representative acids include carboxylic acids,anhydrides, esters and their salts, both metallic and non-metallic. Theorganic compound may contain an ethylenic unsaturation conjugated with acarbonyl group (—C═O). Non-limiting examples include maleic, fumaric,acrylic, methacrylic, itaconic, crotonic, alpha-methyl crotonic, andcinnamic acids as well as their anhydrides, esters and salt derivatives.Maleic anhydride is particularly useful. The unsaturated acid oranhydride may be present in the tackifier at about 0.1 wt % to 10 wt %,or at 0.5 wt % to 7 wt %, or at 1 to 4 wt %, based upon the weight ofthe hydrocarbon resin and the unsaturated acid or anhydride.

The tackifier, if present, is typically present at 1 wt % to 50 wt %,based upon the weight of the blend, or 10 wt % to 40 wt %, or 20 wt % to40 wt %. Generally however, tackifier is not present, or if present, ispresent at less than 10 wt %, or less than 5 wt %, or at less than 1 wt%.

In another form, the polymer blends produced by the processes disclosedherein further comprise a crosslinking agent. The crosslinking agent maybe blended either in-line by the processes disclosed herein (see FIG.11), in-line via an extrusion process downstream of in-linepolymerization/separation/blending processes disclosed herein, or in anoff-line compounding process. Useful crosslinking agents include thosehaving functional groups that can react with the acid or anhydride groupand include alcohols, multiols, amines, diamines and/or tramlines.Non-limiting examples of crosslinking agents useful include polyaminessuch as ethylenediamine, diethylenetriamine, hexamethylenediamine,diethylaniinopropylamine, and/or menthanediamine.

In another form, the polymer blends produced by the processes disclosedherein, and/or blends thereof, further comprise typical additives knownin the art such as fillers, cavitating agents, antioxidants,surfactants, adjuvants, plasticizers, block, antiblock, colormasterbatches, pigments, dyes, processing aids, UV stabilizers,neutralizers, lubricants, waxes, nucleating agents and/or clarifyingagents. These additives may be present in the typically effectiveamounts well known in the art, such as 0.001 wt % to 10 wt %. Theseadditive may be blended either in-line by the processes disclosed herein(see FIG. 11), in-line via an extrusion process downstream of in-linepolymerization/separation/blending processes disclosed herein, or in anoff-line compounding process.

Useful fillers, cavitating agents and/or nucleating agents includetitanium dioxide, calcium carbonate, barium sulfate, silica, silicondioxide, carbon black, sand, glass beads, mineral aggregates, talc, clayand the like. Nucleating agents of the non-clarifying type include, butare not limited to, sodium benzoate, Amfine NA 11, Amfine NA 21, andMilliken HPN 68.

Useful antioxidants and UV stabilizers include phenolic antioxidants,such as Irganox 1010, Irganox 1076 both available from Ciba-Geigy. Oilsmay include paraffinic or naphthenic oils such as Primol 352, or Primol876 available from ExxonMobil Chemical France, S.A. in Paris, France.The oils may include aliphatic naphthenic oils, white oils or the like.

Plasticizers and/or adjuvants may include mineral oils, polybutenes,phthalates and the like. The plasticizers may include phthalates such asdiisoundecyl phthalate (DIUP), diisononylphthalate (DINP),dioctylphthalates (DOP) and polybutenes, such as Parapol 950 and Parapol1300 available from ExxonMobil Chemical Company in Houston Texas.Additional plasticizers include those disclosed in WO0118109A1, U.S.patent application Ser. No. 10/640,435, and U.S. patent application Ser.No. 11/177,004, which are incorporated by reference herein with regardto plasticizer compositions and blending thereof.

Useful processing aids, lubricants, waxes, and/or oils include lowmolecular weight products such as wax, oil or low M_(n) polymer, (lowmeaning below M_(n) of 5000, or below 4000, or below 3000, or below2500). Useful waxes include polar or non-polar waxes, functionalizedwaxes, polypropylene waxes, polyethylene waxes, and wax modifiers.

Useful functionalized waxes include those modified with an alcohol, anacid, or a ketone. Functionalized means that the polymer has beencontacted with an unsaturated acid or anhydride. Useful unsaturatedacids or anhydrides include any unsaturated organic compound containingat least one double bond and at least one carbonyl group. Representativeacids include carboxylic acids, anhydrides, esters and their salts, bothmetallic and non-metallic. The organic compound may contain an ethylenicunsaturation conjugated with a carbonyl group (—C═O). Non-limitingexamples include maleic, fumaric, acrylic, methacrylic, itaconic,crotonic, alpha-methyl crotonic, and cinnamic acids as well as theiranhydrides, esters and salt derivatives. Maleic anhydride isparticularly useful. The unsaturated acid or anhydride may be present at0.1 wt % to 10 wt %, or at 0.5 wt % to 7 wt %, or at 1 to 4 wt %, basedupon the weight of the hydrocarbon resin and the unsaturated acid oranhydride. Examples include waxes modified by methyl ketone, maleicanhydride or maleic acid. Low Mn polymers include polymers of loweralpha olefins such as propylene, butene, pentene, hexene and the like. Auseful polymer includes polybutene having an Mn of less than 1000 g/mol.An example of such a polymer is available under the trade name PARAPOL™950 from ExxonMobil Chemical Company. PARAPOL™ 950 is a liquidpolybutene polymer having an Mn of 950 g/mol and a kinematic viscosityof 220 cSt at 100° C., as measured by ASTM D 445.

Useful clarifying agents include, but are not limited to, thebenzalsorbitol family of clarifiers, and more particularlydibenzalsorbitol (Millad 3905), di-p-methylbenzalsorbitol (Milliad3940), and bis-3,4-dimethylbenzalsorbitol (Milliad 3988).

EXAMPLES

Disclosure Propylene Polymerization Examples at SupercriticalConditions:

All polymerizations were performed in bulk polymerization systems (i.e.,without using solvent, except for what was introduced with the catalystsolution, which did not exceed 10 wt %) and without monomer recycle.

All polymerization experiments were performed in a continuous stirredtank reactor (CSTR) made by Autoclave Engineers, Erie Pa. The reactorwas designed for operating at a maximum pressure and temperature of 207MPa (30 kpsi) and 225° C., respectively. The nominal reactor volume was150 mL with a working volume of 127 mL (working volume lower due toreactor internals). The reactor was equipped with an electric heater andwith a stirrer with a magnetic drive. A pressure transducer located onthe monomer feed line measured the pressure in the reactor. Thetemperature was measured inside the reactor using a type-K thermocouple.The reactor was protected against over-pressurization by automaticallyopening an air-actuated valve (High Pressure Company, Erie, Pa.) in casethe reactor pressure exceeded the preset limit. A flush-mounted rupturedisk located on the side of the reactor provided further protectionagainst catastrophic pressure failure. All product lines were heated to˜150° C. to prevent fouling. The reactor body had two heating bands thatwere controlled by a programmable logic control device (PLC). Thereactor did not have cooling capability. Once the reactor lined outduring polymerization, its temperature was controlled manually byadjusting the flow rates of the monomer and catalyst feeds. No externalheating was necessary in most experiments, i.e. the reactor temperaturewas maintained by controlling the heat released by the polymerizationprocess.

Two independent lock-hopper assemblies were used to manage the effluentflow from the reactor: one for waste collection during start up and shutdown, and the other one for product collection during the balance periodat lined out, steady state conditions. Each lock-hopper consisted of twoair-actuated valves bracketing a short piece of high-pressure tubing.Changing the internal diameter and/or the length of the lock-hopper tubeallowed the adjustment of the volume of the lock-hoppers. Aliquots ofthe reactor content were taken out continuously by running thelock-hopper valves in cycles. One lock-hopper cycle consisted of firstopening and closing of the valve between the lock-hopper tube and thereactor followed by opening and closing the downstream valve.Adjustments in the frequency of the lock-hopper cycles allowedmaintaining the desired reactor pressure at a preset feed rate. Thevolume and the frequency of the two lock-hoppers were always set thesame to allow switching between the lock-hoppers without affecting thesteady state condition of the reactor. A drain port on the bottom of thereactor was used to empty the reactor after each experiment.

The application of lock-hoppers for product removal afforded robustreactor operations independent of the properties of the polymer madeand/or the polymer concentration in the effluent. This operation mode,however, introduced short-term fluctuations both in the pressure and thetemperature of the reactor. Typical pressure and temperaturefluctuations caused by the operation of the lock-hopper at 207 MPa (30kpsi) reactor pressure were less than 20.7 MPa (3 kpsi) and 1.5° C.,respectively. The reported reaction pressure and temperature values wereobtained by calculating the averages of the pressure and temperaturedata acquired during the entire time of product collection, which can bereferred to as balance period.

Propylene was fed from low-pressure cylinders equipped with a dip legfor liquid delivery to the reactor. Heating blankets provided heat toincrease the cylinder head pressure to deliver the monomer to the feedpump at a pressure above the bubble point of the feed. The low-pressuremonomer feed was also stabilized against bubble formation by cooling thepump head using chilled water running at 10° C. The monomer feed waspurified using two separate beds in series: activated copper (reduced inflowing H₂ at 225° C. and 1 bar) for oxygen removal and molecular sieve(5A, activated in flowing N₂ at 270° C.) for water removal. The purifiedmonomer feed was fed by a diaphragm pump (Model MhS 600/11, ProMinentOrlita, Germany) through the stirrer head into the reactor. The monomerflow rate was measured by a Coriolis mass flow meter (Model PROlinePromass 80, Endress and Hauser) that was located downstream of thepurification traps on the low-pressure side of the feed pump. Thepressure fluctuation in the reactor caused some minor fluctuation in thefeed rate. The reported feed flows were determined by averaging the flowrate during the entire balance period.

The catalyst feed solution was prepared inside an argon-filled dry box(Vacuum Atmospheres). The atmosphere in the glove box was purified tomaintain <1 ppm O₂ and <1 ppm water. All glassware was oven-dried for aminimum of 4 hours at 120° C. and transferred hot to the antechamber ofthe dry box. Stock solutions of the catalyst precursors and theactivators were prepared using purified toluene and stored in amberbottles inside the dry box. Aliquots were taken to prepare freshactivated catalyst solutions before each polymerization experiment.Catalyst concentrations of the catalyst feed were adjusted to maintainthe target reaction temperature at feed rates that introduced not morethan 3 to 8 wt % of catalyst solvent (toluene) into the reactor. Due tothe small scale and daily start-ups of our reactor, impurity levels weredifficult to stabilize, thus catalytic activities varied from run torun. Nonetheless, catalytic activities were very high, particularly withnon-coordinating anion activators, typically requiring catalystconcentrations on the order of 10 to 100 mol ppb in the combined feed tothe reactor.

In a typical experiment, the reactor was preheated to ˜10 to 15° C.below that of the desired reaction temperature. During the line-outperiod, the catalyst feed and lock-hopper rates were adjusted to reachand maintain the target reaction temperature and pressure. Once thereactor reached steady state at the desired conditions, productcollection was switched from the waste collection to the on-balanceproduct collection vessel. The reactor was typically run on-balancebetween 30 to 90 min, after which the effluent was redirected to thewaste collection vessel and the reactor was shut down. The products werecollected from the on-balance vessel. The products were vacuum-driedovernight at 70° C. before characterization. The conversion and reactionrates were determined based on the total feed used and the product yieldduring the balance period.

Catalyst productivity, expressed as g product per g catalyst, is theproduct of catalyst activity and residence time. In order to generate ascalable kinetic characterization parameter for catalytic activity, wealso determined the turnover frequency (TOF), expressed as mol monomerconverted per mol catalyst in one second. TOF was calculated by dividingthe average monomer conversion rate with the average catalyst inventoryin the reactor. The latter in turn was determined by multiplying thecatalyst feed rate with the residence time of the reaction medium. Theresidence time was derived from the reactor free volume and thevolumetric flow rate of the reaction medium. The total mass flow wasgenerated by summing of the individual feed flows. In order to convertmass flows into volumetric flows, the density of the reaction medium wascalculated using a proprietary thermodynamic software. The softwareenabled the calculation of the density of polymer-containing blends atreactor conditions.

Anhydrous toluene from Sigma-Aldrich was used in catalyst preparationand for reactor flushing. Initially, it was used as received (18-literstainless steel vessels, N₂ head pressure) for reactor rinsing andflushing. Later, copper and molecular sieve traps were installed in thetoluene feed line, the description of which is given earlier for the gasfeed (vide supra). Propylene Grade 2.5 (BOC) was obtained in #100low-pressure cylinders. The methylaluminoxane (MAO) activator (10 wt %in toluene) was purchased from Albermarle Corporation and was used asreceived. Tri-isobutylaluminum (Sigma-Aldrich) was used for aestivatingthe feed line and the reactor if they were exposed to air duringmaintenance.

Tables 1a, 1b, and 1c list the catalyst precursor compositions,activators, MFR and NMR results (see also the footnotes of the tables).Tables 2a and 2b list the thermal properties (crystallization andmelting data) and molecular weight data for the disclosed polypropylenesmade at the conditions described in Tables 1a, 1b, and 1c. Note thateach disclosed product listed in these tables is identified by a uniquesample ID in the first column in Tables 1a, 1b, and 1c. These ID numbersare the same as those listed in Tables 2a and 2b. Melting andcrystallization data listed were obtained at a cooling rate of 10°C./min using differential scanning calorimetry (DSC). Details of theexperimental conditions are described later (vide infra). Heat of fusionof the melting endothermic listed in the column indicated by ΔHf isconverted to % crystallinity as described later (vide infra). Thedifference between melting peak temperature (Tmp) and crystallizationpeak temperature (Tcp) is listed in the column indicated as supercoolingrange (Tmp−Tcp). Supercooling limit (SCL) is calculated usingSCL=0.907Tmp−99.64 where SCL is the limiting Tmp−Tcp separatingcomparative and novel polypropylenes. Comparative polypropylenes haveexperimental Tmp−Tcp values larger than the SCL values, while theTmp−Tcp values for the novel polypropylenes are equal or fall below theSCL values. Molecular weight (Mw, Mn, Mz) listed in these tables areobtained via GPC (details given later—vide infra).

FIG. 1 shows a plot of supercooling range (Tmp−Tcp) (data from Tables 2aand 2b) plotted against peak melting temperature (Tmp). Also plotted inthis figure are comparative polypropylene products obtained fromsolution and slurry processes. As FIG. 1 demonstrates, the novelpolypropylenes, from a variety of catalysts, cluster separately from thecomparative products, showing a reduced supercooling range for productswith the same melting peak temperature. This in turn affords bettercrystallization properties for the novel disclosure products compared tocomparative polypropylenes with identical melting peak temperatures.Tables 3 and 4 describe the process conditions and characterization datafor the comparative solution products, while Tables 5, 6 and 7 show thecorresponding details of the comparative slurry products. Note that incomparison, polypropylenes made with the process described herein showlower supercooling ranges(i.e., are at or fall below the SCL values)than comparative products. At a given peak melting temperature theseproducts show higher peak crystallization temperature (lower values ofsupercooling Tmp−Tcp) than comparative products. The highercrystallization temperature (Tcp) implies faster crystallizability,without the need for external nucleating agents, versus the comparativepolypropylene products from other processes. This is a desirableattribute for end-use articles such as films, fibers and fabrics, moldedparts.

TABLE 1a Process Conditions, MFR, and NMR Results for InventivePolypropylenes Precursor Reactor Catalyst Pentads Regio SampleMetallocene Central Cl₂/ Temp Pressure Productivity MFR mol fractionDefects/ ID Ligand Atom Me₂ Activator ° C. MPa kg P/g prec g/10 min mmmm10,000 C₃ ⁼ S1 1 Zr Cl2 MAO 124 72.6 87 76 0.991 81 S2 1 Zr Cl2 MAO 12472.6 128 107 0.992 84 S3 1 Zr Cl2 MAO 121 75.5 39 39 0.989 75 S4 1 ZrCl2 MAO 122 133.2 82 10 0.994 79 S5 1 Zr Cl2 MAO 120 137.7 43 15 0.99275 S6 1 Zr Cl2 MAO 124 139.9 91 34 0.990 81 S7 1 Zr Cl2 MAO 123 143.3 8233 0.987 87 S8 1 Zr Cl2 MAO 122 194.5 38 43 0.988 95 S9 1 Zr Cl2 MAO 120210.9 46 8 0.994 84 S10 1 Zr Cl2 MAO 119 212.2 115 9 0.989 85 S11 1 ZrCl2 MAO 127 70.9 851 180 0.989 84 S12 1 Zr Cl2 MAO 128 70.1 626 57 1.00168 S13 1 Zr Cl2 MAO 129 137.3 61 23 0.984 88 S14 1 Zr Cl2 MAO 130 204.858 18 0.988 96 S15 1 Zr Me2 B1 100.1 40.2 632 18 0.990 44 S16 1 Zr Me2B1 102.2 73.3 491 6 0.990 48 S17 1 Zr Me2 B1 106.9 72.7 807 26 0.990 52S18 1 Zr Me2 B1 119.1 39.3 1224 80 0.988 53 S19 1 Zr Me2 B1 120.3 40.21093 122 0.983 52 S20 1 Zr Me2 B1 116.8 71.9 33 58 0.983 56 S21 1 Zr Me2B1 119.1 71.9 1358 38 0.986 56 S22 1 Zr Me2 B1 119.4 138.7 283 19 0.98962 S23 1 Zr Me2 B1 117.8 139.0 178 15 0.988 60 S24 1 Zr Me2 B1 126.733.8 1364 149 0.983 60 S25 5 Hf Cl2 MAO 121 137.6 31 11 0.994 80 S26 5Hf Cl2 MAO 122 138.7 33 54 0.993 76 S27 4 Zr Cl2 MAO 113 60.7 112 150.993 61 S28 4 Zr Cl2 MAO 113 62.9 129 26 0.984 65 S29 4 Zr Cl2 MAO 11171.7 134 24 0.991 61 S30 4 Zr Cl2 MAO 112 73.7 160 19 0.992 63 Ligands:1 = rac-dimethylsilyl-bis(2-methyl, 4-phenylindenyl), 2 =rac-dimethylsilyl-bis(2-isopropyl, 4-naphthylindenyl), 3 =rac-dimethylsilyl-bis(2-methyl, 4-naphthylindenyl), and 4 =rac-dimethylsilyl-bis(2-methyl, 4-(3′,5′-di-tert-butyl-phenyl)indenyl).Activators: MAO = methylaluminoxane, B1 =N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, and C =N,N-dimethylaniliniumtetrakis(heptafluoronaphthyl)borate.

TABLE 1b Process Conditions, MFR, and NMR Results for InventivePolypropylenes Precursor Reactor Catalyst Pentads Regio SampleMetallocene Central Cl₂/ Temp Pressure Productivity MFR mol fractionDefects/ ID Ligand Atom Me₂ Activator ° C. MPa kg P/g prec g/10 min mmmm10,000 C₃ ⁼ S31 4 Zr Cl2 MAO 112 74.6 150 12 0.989 56 S32 4 Zr Cl2 MAO110.1 75.3 138 11 0.994 61 S33 4 Zr Cl2 MAO 111 202.5 79 2 0.995 72 S344 Zr Cl2 MAO 116 36.7 145 63 0.995 75 S35 4 Zr Cl2 MAO 117 36.7 150 850.995 58 S36 4 Zr Cl2 MAO 116 48.3 160 45 0.990 69 S37 4 Zr Cl2 MAO 11660.3 165 30 0.994 67 S38 4 Zr Cl2 MAO 114 61.1 164 31 0.989 70 S39 4 ZrCl2 MAO 114 62.9 153 26 0.992 69 S40 4 Zr Cl2 MAO 114 63.5 143 30 0.98966 S41 4 Zr Cl2 MAO 118 48.1 127 51 0.996 65 S42 4 Zr Cl2 MAO 118 48.2150 73 0.995 64 S43 4 Zr Cl2 MAO 120 48.2 147 77 0.999 75 S44 4 Zr Cl2MAO 118 48.4 158 69 0.998 66 S45 4 Zr Cl2 MAO 118 49.1 158 64 0.997 65S46 4 Zr Cl2 MAO 120 202.0 111 8 0.996 68 S47 4 Zr Me2 C 103.2 204.0 1071 0.992 48 S48 4 Zr Me2 B1 111 48.3 23 12 0.995 39 S49 4 Zr Me2 B1 11454.4 33 21 0.994 41 S50 4 Zr Me2 B1 114.2 57.3 611 17 0.995 43 S51 4 ZrMe2 B1 117 51.6 39 22 0.995 45 S52 4 Zr Me2 B1 116.7 58.0 76 28 0.994 44S53 4 Zr Me2 B1 117.8 56.2 519 32 0.991 44 S54 4 Zr Me2 B1 118 56.0 13627 0.992 44 S55 4 Zr Me2 B1 118 57.6 80 37 0.992 45 S56 4 Zr Me2 B1118.1 55.6 717 36 0.991 46 S57 4 Zr Me2 B1 118.1 56.0 431 29 0.991 46S58 4 Zr Me2 B1 118 49.6 46 87 0.994 46 S59 4 Zr Me2 B1 118.2 57.4 20735 0.993 48 S60 4 Zr Me2 B1 118.6 57.3 682 30 0.990 45 Ligands: 1 =rac-dimethylsilyl-bis(2-methyl, 4-phenylindenyl), 2 =rac-dimethylsilyl-bis(2-isopropyl, 4-naphthylindenyl), 3 =rac-dimethylsilyl-bis(2-methyl, 4-naphthylindenyl), and 4 =rac-dimethylsilyl-bis(2-methyl, 4-(3′,5′-di-tert-butyl-phenyl)indenyl).Activators: MAO = methylaluminoxane, B1 =N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, and C =N,N-dimethylaniliniumtetrakis(heptafluoronaphthyl)borate.

TABLE 1c Process Conditions, MFR, and NMR Results for inventivePolypropylenes Precursor Reactor Catalyst Pentads Regio SampleMetallocene Central Cl₂/ Temp Pressure Productivity MFR mol fractionDefects/ ID Ligand Atom Me₂ Activator ° C. MPa kg P/g prec g/10 min mmmm10,000 C₃ ⁼ S61 4 Zr Me2 B1 119 49.3 46 65 0.990 43 S62 4 Zr Me2 B1118.7 58.9 974 37 0.991 46 S63 4 Zr Me2 B1 118.7 56.9 576 34 0.992 44S64 4 Zr Me2 B1 118.7 57.6 207 28 0.994 47 S65 4 Zr Me2 B1 118.9 55.8458 37 0.991 46 S66 4 Zr Me2 B1 119 56.0 599 38 0.989 45 S67 4 Zr Me2 B1119.2 57.8 505 53 0.993 47 S68 4 Zr Me2 B1 119.2 56.4 513 38 0.990 46S69 4 Zr Me2 B1 119.2 56.2 474 34 0.989 45 S70 4 Zr Me2 B1 119.2 56.4481 39 0.984 48 S71 4 Zr Me2 B1 119.3 57.4 200 35 0.992 45 S72 4 Zr Me2B1 119.3 55.7 523 37 0.989 46 S73 4 Zr Me2 B1 119.3 56.2 346 37 0.986 47S74 4 Zr Me2 B1 119.3 56.2 714 34 0.991 46 S75 4 Zr Me2 B1 119.4 51.6 4054 0.993 50 S76 4 Zr Me2 B1 121 52.0 100 50 0.992 51 S77 4 Zr Me2 B1 12057.2 916 37 0.988 48 S78 4 Zr Me2 B1 119.8 58.0 539 46 0.993 47 S79 2 ZrCl2 MAO 112 134.8 119 1894 0.982 41 S80 2 Zr Cl2 MAO 112 136.5 128 17240.987 32 S81 2 Zr Cl2 MAO 112 135.6 89 1590 0.970 27 S82 2 Zr Cl2 MAO109 137.7 126 1476 0.989 35 S83 2 Zr Cl2 MAO 110 197.6 100 620 0.985 39S84 2 Zr Cl2 MAO 121 197.3 68 2418 0.979 40 S85 3 Zr Cl2 MAO 111 187.671 2 0.995 89 S86 3 Zr Cl2 MAO 112 194.5 130 11 0.993 106 S87 3 Zr Cl2MAO 123 192.0 140 19 0.983 64 Ligands: 1 =rac-dimethylsilyl-bis(2-methyl, 4-phenylindenyl), 2 =rac-dimethylsilyl-bis(2-isopropyl, 4-naphthylindenyl), 3 =rac-dimethylsilyl-bis(2-methyl, 4-naphthylindenyl), and 4 =rac-dimethylsilyl-bis(2-methyl, 4-(3′,5′-di-tert-butyl-phenyl)indenyl).Activators: MAO = methylaluminoxane, B1 =N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, and C =N,N-dimethylaniliniumtetrakis(heptafluoronaphthyl)borate.

TABLE 2a Thermal Characterization and GPC results for InventivePolypropylenes Crystallization Melting (DSC) (2nd Heat) (DSC) Tmp − TcpDRI (GPC) Sample T_(c,onset) T_(c,peak) T_(m,peak) ΔH_(f) Cryst.Supercooling SCL Mz Mw Mn ID ° C. ° C. ° C. J/g % ° C. ° C. kg/molkg/mol kg/mol Mw/Mn Mz/Mw S1 119.1 116.0 151.5 100.7 48.6 35.5 37.8235.5 119.9 55.4 2.16 1.96 S2 116.2 113.0 149.3 104.0 50.2 36.3 35.8261.5 134.5 65.5 2.05 1.94 S3 117.6 113.5 150.7 92.2 44.5 37.2 37.0252.0 149.6 64.0 2.34 1.68 S4 117.7 114.5 150.3 103.7 50.1 35.8 36.7321.7 206.9 109.7 1.89 1.55 S5 117.6 114.4 150.1 98.7 47.6 35.7 36.5329.5 202.9 84.8 2.39 1.62 S6 115.4 111.8 149.7 101.8 49.1 37.9 36.1270.5 172.5 88.3 1.95 1.57 S7 115.6 111.1 149.1 97.7 47.2 38.0 35.6305.7 185.5 89.0 2.08 1.65 S8 115.1 110.9 148.1 80.4 38.8 37.2 34.7265.9 153.9 50.3 3.06 1.73 S9 116.8 113.4 149.2 88.0 42.5 35.8 35.7425.3 267.4 122.1 2.19 1.59 S10 116.7 113.3 149.9 88.3 42.6 36.6 36.3395.2 247.6 119.1 2.08 1.60 S11 117.2 113.9 149.8 98.5 47.6 35.9 36.2175.5 106.4 53.3 2.00 1.65 S12 118.7 114.1 150.8 97.3 47.0 36.7 37.1240.4 145.4 71.7 2.03 1.65 S13 115.9 113.0 150.6 111.1 53.6 37.6 37.0287.9 168.6 57.6 2.93 1.71 S14 115.2 111.0 148.9 87.4 42.2 37.9 35.4323.5 198.8 80.8 2.46 1.63 S15 121.3 115.5 155.0 100.1 48.3 39.5 40.9340.7 207.5 102.2 2.03 1.64 S16 116.9 113.3 153.4 93.8 45.3 40.1 39.5475.0 271.0 137.5 1.97 1.75 S17 117.8 113.7 151.9 87.2 42.1 38.2 38.2431.5 258.7 118.8 2.18 1.67 S18 119.4 114.7 153.5 96.6 46.6 38.8 39.6207.5 129.9 68.7 1.89 1.60 S19 120.6 116.7 152.6 100.6 48.6 35.9 38.8176.9 110.0 55.7 1.97 1.61 S20 116.7 113.2 152.4 93.8 45.3 39.2 38.6262.9 161.8 83.4 1.94 1.62 S21 118.4 114.5 151.3 94.7 45.7 36.8 37.6285.9 179.0 94.9 1.89 1.60 S22 115.7 113.0 151.1 96.8 46.7 38.1 37.4322.1 195.9 92.2 2.12 1.64 S23 116.4 113.3 152.9 99.1 47.8 39.7 39.0240.0 145.8 74.3 1.96 1.65 S24 117.0 112.8 150.8 99.3 47.9 38.0 37.1307.5 165.8 69.4 239 1.85 S25 116.2 112.6 150.7 103.1 49.8 38.1 37.0352.7 229.3 118.3 1.94 1.54 S26 116.1 112.4 149.7 91.9 44.4 37.3 36.1219.8 137.4 72.0 1.91 1.60 S27 118.4 115.3 152.6 87.7 42.3 37.3 38.8334.4 200.4 100.2 2.00 1.67 S28 117.6 114.0 152.1 97.2 46.9 38.1 38.3297.0 181.2 91.4 1.98 1.64 S29 119.9 116.6 153.8 100.9 48.7 37.2 39.9339.2 204.1 100.2 2.04 1.66 S30 118.6 115.9 153.1 99.8 48.2 37.2 39.2314.1 189.2 94.1 2.01 1.66 S31 116.7 113.4 151.5 93.0 44.9 38.1 37.8389.4 230.1 105.7 2.18 1.69 S32 119.6 116.7 154.3 101.7 49.1 37.6 40.3378.9 230.9 115.8 1.99 1.64 S33 119.3 116.2 153.3 104.0 50.2 37.1 39.4581.0 360.7 171.6 2.10 1.61 S34 117.9 114.5 153.4 98.5 47.6 38.9 39.5255.7 151.9 76.7 1.98 1.68 S35 117.4 114.3 153.4 97.1 46.9 39.1 39.5239.8 143.8 73.5 1.96 1.67 S36 118.1 114.8 152.9 100.0 48.3 38.1 39.0252.0 152.2 77.5 1.96 1.66 S37 117.1 114.0 151.6 101.8 49.1 37.6 37.9265.5 155.8 76.8 2.03 1.70 S38 118.4 116.0 152.1 101.6 49.0 36.1 38.3277.3 167.6 84.3 1.99 1.65 S39 117.9 114.7 152.3 96.5 46.6 37.6 38.5265.5 161.6 82.6 1.96 1.64 S40 117.8 114.1 154.0 93.7 45.2 39.9 40.0301.4 180.2 88.8 2.03 1.67 S41 118.3 114.7 153.1 98.2 47.4 38.4 39.2257.1 153.2 76.7 2.00 1.68 S42 120.3 116.8 153.0 99.7 48.1 36.2 39.1260.4 153.0 76.0 2.01 1.70 S43 117.6 114.1 152.2 95.5 46.1 38.1 38.4235.7 140.3 70.1 2.00 1.68 S44 117.5 114.3 152.0 96.5 46.6 37.7 38.2243.2 143.3 70.6 2.03 1.70 S45 120.0 116.0 154.0 99.9 48.2 38.0 40.0235.8 141.1 68.7 2.06 1.67 S46 119.8 115.4 152.6 99.0 47.8 37.2 38.8432.7 272.5 130.7 2.08 1.59 Supercooling Limit (SCL) given by SCL =0.907x − 99.64, where x is Tmp In the above examples S1 to S46,branching index (g′) values ranged between 0.874 to 1.074.

TABLE 2b Thermal Characterization and GPC results for InventivePolypropylenes Crystallization Melting (DSC) (2nd Heat) (DSC) Tmp − TcpDRI (GPC) T_(c,onset) T_(c,peak) T_(m,peak) ΔH_(f) Cryst. SupercoolingSCL Mz Mw Mn Sample ID ° C. ° C. ° C. J/g % ° C. ° C. kg/mol kg/molkg/mol Mw/Mn Mz/Mw S47 117.4 114.2 155.5 90.5 43.7 41.4 41.4 678.3 436.5215.8 2.02 1.55 S48 118.5 114.7 156.6 97.5 47.1 41.9 42.4 298.2 189.998.1 1.94 1.57 S49 117.2 114.3 155.1 98.4 47.5 40.8 41.0 239.1 151.779.8 1.90 1.58 S50 120.2 115.0 155.8 96.2 46.4 40.8 41.7 361.8 226.1118.6 1.91 1.60 S51 119.9 115.0 155.8 95.5 46.1 40.8 41.7 323.1 205.9111.0 1.86 1.57 S52 118.1 114.5 155.2 97.3 47.0 40.7 41.1 326.0 199.098.9 2.01 1.64 S53 118.4 114.5 154.5 98.9 47.7 40.0 40.5 303.0 188.196.3 1.95 1.61 S54 118.0 114.4 155.8 97.3 47.0 41.4 41.7 334.3 200.292.0 2.18 1.67 S55 117.9 113.6 155.2 97.3 47.0 41.6 41.1 268.6 168.491.0 1.85 1.59 S56 118.3 114.3 155.3 99.6 48.1 41.0 41.2 278.6 174.489.0 1.96 1.60 S57 118.1 114.5 155.0 99.4 48.0 40.5 40.9 315.3 193.595.8 2.02 1.63 S58 118.4 114.9 155.3 98.8 47.7 40.4 41.2 496.2 188.639.7 4.76 2.63 S59 117.4 113.9 155.1 97.9 47.3 41.2 41.0 278.4 176.496.2 1.83 1.58 S60 117.0 113.5 155.2 97.4 47.0 41.7 41.1 304.5 187.294.3 1.98 1.63 S61 119.9 115.2 155.8 96.1 46.4 40.6 41.7 300.9 187.192.1 2.03 1.61 S62 119.6 115.2 155.5 95.4 46.1 40.3 41.4 286.6 178.794.7 1.89 1.60 S63 119.5 115.1 155.5 97.6 47.1 40.4 41.4 272.4 173.296.3 1.80 1.57 S64 118.6 114.6 155.1 99.2 47.9 40.5 41.0 265.8 168.693.6 1.80 1.58 S65 119.0 115.3 155.4 97.3 47.0 40.1 41.3 293.9 178.790.0 1.99 1.65 S66 118.1 114.8 155.4 100.9 48.7 40.6 41.3 280.4 171.585.5 2.01 1.64 S67 116.3 113.6 153.5 96.6 46.6 39.9 39.6 268.1 169.583.3 2.03 1.58 S68 119.1 115.3 155.5 98.9 47.7 40.2 41.4 284.5 178.794.4 1.89 1.59 S69 118.7 115.3 155.4 99.9 48.2 40.1 41.3 293.1 182.092.8 1.96 1.61 S70 119.2 115.0 155.7 100.1 48.3 40.7 41.6 284.3 179.795.2 1.89 1.58 S71 116.5 113.7 154.2 97.4 47.0 40.5 40.2 262.0 163.286.3 1.89 1.61 S72 119.4 115.7 154.8 97.2 46.9 39.1 40.8 284.4 176.692.8 1.90 1.61 S73 118.5 114.9 154.7 101.3 48.9 39.8 40.7 272.0 173.395.1 1.82 1.57 S74 118.1 114.3 155.3 100.2 48.4 41.0 41.2 287.2 176.187.8 2.00 1.63 S75 119.3 114.8 154.8 101.1 48.8 40.0 40.8 255.1 157.679.3 1.99 1.62 S76 117.9 114.3 154.6 97.9 47.3 40.3 40.6 230.0 144.378.7 1.83 1.59 S77 119.5 115.5 156.0 97.7 47.2 40.5 41.9 296.5 182.392.5 1.97 1.63 S78 116.7 113.9 154.1 98.8 47.7 40.2 40.1 248.1 154.783.0 1.86 1.60 S79 119.4 116.6 151.6 103.3 49.9 35.0 37.9 91.8 57.3 28.62.00 1.60 S80 118.5 115.2 151.1 100.4 48.5 36.0 37.4 92.6 58.5 28.9 2.021.58 S81 119.6 115.9 151.3 104.9 50.6 35.4 37.6 97.9 59.3 28.1 2.11 1.65S82 119.3 116.1 152.2 108.0 52.1 36.1 38.4 100.7 62.3 28.8 2.17 1.62 S83119.0 115.7 152.9 106.5 51.4 37.2 39.0 115.4 70.2 32.8 2.14 1.65 S84117.6 115.1 151.6 105.4 50.9 36.5 37.9 92.6 58.5 30.6 1.91 1.58 S85117.8 114.3 152.0 94.7 45.7 37.7 38.2 576.6 359.7 166.3 2.16 1.60 S86116.6 111.1 149.3 99.0 47.8 38.2 35.8 392.2 246.0 116.4 2.11 1.59 S87115.5 111.9 148.8 85.4 41.2 36.9 35.3 306.7 192.8 93.8 2.06 1.59Supercooling Limit (SCL) given by SCL = 0.907x − 99.64, where x is Tmp.In the above examples S47 to S87, branching index (g′) values rangedbetween 0.874 to 1.074.

Solution Polymerization (Comparative Examples)

All the solution polymerizations were performed in a liquid filled,single-stage continuous stirred tank reactor (CSTR). The reactor was a0.5-liter stainless steel autoclave and was equipped with a stirrer, awater cooling/steam heating element with a temperature controller, and apressure controller. Solvents and propylene were first purified bypassing through a three-column purification system. The purificationsystem consisted of an Oxiclear column (Model # RGP-R1-500 fromLabclear) followed by a 5A and a 3A molecular sieve column. Purificationcolumns were regenerated periodically whenever there was evidence oflower activity of polymerization. The purified solvents and monomerswere then chilled to about −15 C by passing through a chiller before fedinto the reactor through a manifold. Solvent and monomers were mixed inthe manifold and fed into reactor through a single tube. All liquid flowrates were measured using Brooksfield mass flow meters or Micro-MotionCoriolis-type flow meters.

The metallocene catalyst precursors shown in Table 3 were pre-activatedat a precursor/activator molar ratio of about 1:1 in toluene. Allcatalyst solutions were kept in an inert atmosphere with <1.5 ppm watercontent and fed into the reactor by a metering pump through a separateline. Contact between catalyst and monomer took place in the reactor.

As an impurity scavenger, 250 mL of tri-n-octyl aluminum (TNOAl) (25 wt% in hexane, Sigma Aldrich) was diluted in 22.83 kg of hexane. The TNOAlsolution was stored in a 37.9-liter cylinder under nitrogen blanket. Thesolution was used for all polymerization runs until about 90% ofconsumption, then a new batch was prepared. Pumping rates of the TNOAlsolution varied from run to run, typically ranging from 0 (no scavenger)to 4 mL/min.

The reactor was first cleaned by nitrogen purge and solvent wash. Aftercleaning, the reactor was heated/cooled to the desired temperature usingwater/steam mixture flowing through the reactor jacket and controlled ata set pressure with controlled solvent flow. Monomers, catalystsolutions and scavenger solution were then fed into the reactor. Anautomatic temperature control system was used to control and maintainthe reactor at a set temperature. Onset of polymerization activity wasdetermined by observations of a viscous product and lower temperature ofwater-steam mixture. Once the activity was established and systemreached steady-state, the reactor was lined out by continuing operatingthe system under the established condition for a time period of at leastfive times of mean residence time prior to sample collection. Theresulting mixture, containing mostly solvent, polymer and unreactedmonomer, was collected in a collection box after the system reached asteady-state operation. The collected samples were first air-dried in ahood to evaporate most of the solvent, and then dried in a vacuum ovenat a temperature of about 90 C for about 12 hours. The vacuum-driedsamples were weighed to obtain yields. All reactions were carried out ata pressure of about 2.41 MPa gauge.

TABLE 3 Catalyst systems used for generating Comparative Polypropylenesfrom Solution Polymerization Example Catalyst Activator SO1 1 B1 SO2 1B1 SO3 1 B1 SO4 1 B1 SO5 1 B1 SO6 1 B2 SO7 1 B2 SO8 1 C SO9 1 C SO10 1 CSO11 1 C SO12 1 C SO13 3 B1 SO14 3 B1 SO15 3 B1 SO16 3 C SO17 3 C SO18 3C SO19 4 C SO20 4 C SO21 4 C SO22 4 C Notes: Catalysts: 1 =(rac-dimethylsilyl)bis(2-methyl-4-phenylindenyl)zirconium dimethyl, 3 =(rac-dimethylsilyl)bis(2-methyl-4-naphthylindenyl)zirconium dimethyl,and 4 =(rac-dimethylsilyl)bis(2-methyl-4-(3,′5′-di-tert-butylphenyl)indenyl)zirconiumdimethyl. Activators: B1 =dimethylaniliniumtertrakis(pentafluorophenyl)borate, B2 =trityltertrakis(pentafluorophenyl)borate, and C =dimethylaniliniumtertrakis(heptafluoronaphthyl)borate.

Table 4 below describes the Examples for comparativesolution-polymerized propylene homopolymers, against which the disclosednovel propylene homopolymers were compared.

TABLE 4 Solution-polymerization conditions and product propertiesReactor Cat feed GPC (DRI) DSC data (second heating) Temp rate Mw TmpTmp − Tcp SCL Example (° C.) (mol/min) (kg/mol) (° C.) Tcp (° C.) (° C.)(° C.) SO1 110 2.83E−07 29.4 139.5 105.4 34.1 26.9 SO2 105 2.13E−07 36.6141.0 106.9 34.1 28.2 SO3 100 2.13E−07 47.5 144.1 104.9 39.2 31.0 SO4 952.13E−07 57.0 146.1 109.2 36.9 32.9 SO5 90 2.13E−07 71.9 148.3 110.238.1 34.9 SO6 90 2.83E−07 59.6 144.8 108.0 36.8 31.6 SO7 80 2.83E−0791.7 149.9 109.7 40.2 36.3 SO8 120 2.83E−07 35.2 136.2 100.8 35.4 23.9SO9 110 2.83E−07 60.0 141.5 108.1 33.4 28.7 SO10 100 2.83E−07 96.3 146.4110.4 36.0 33.1 SO11 90  2.3E−07 158.0 151.0 112.0 39.0 37.3 SO12 802.83E−07 ~300 151.6 112.2 39.4 37.8 SO13 110 7.12E−07 32.1 142.7 108.534.2 29.8 SO14 100 1.68E−07 56.8 151.6 111.1 40.5 37.9 SO15 90 5.98E−0860.9 155.8 109.6 46.2 41.7 SO16 120 2.67E−07 30.5 144.2 110.4 33.8 31.1SO17 110 2.24E−08 113.6 153.4 112.6 40.8 39.5 SO18 100 2.24E−08 156.9151.3 112.0 39.3 37.6 SO19 120 1.29E−07 32.1 146.1 110.5 35.5 32.9 SO20110 1.29E−07 50.4 149.5 112.4 37.1 35.9 SO21 100 1.29E−07 81.1 153.2114.0 39.2 39.3 SO22 90 1.29E−07 ~108 155.7 113.8 41.9 41.6 Examples SO1to SO12: C3 monomer feed 14 g/min, hexane solvent 90 ml/min ExamplesSO13 to SO22: C3 monomer feed 14 g/min, hexane solvent 80 ml/minSupercooling Limit (SCL) given by SCL = 0.907x − 99.64, where x is Tmp.

Slurry-polymerized Polypropylenes (Comparative Examples)

Tables 5, 6 and 7 describe prior-art bulk slurry-polymerized propylenehomopolymers and their preparation conditions. The technology formanufacturing propylene homopolymers via bulk slurry polymerization iswell documented in the literature for both conventional Ziegler-Nattacatalysts as well as supported metallocene catalysts.

ACHIEVE™ 1605, 3854 and 6025G1 are commercial homopolymers availablefrom ExxonMobil Chemical Co., Houston, Tex., made in commercialreactors. Slurry Examples SL1 to SL4 are similar to these ACHIEVEproducts. They were manufactured in similar commercial reactors, but theprocess conditions were adjusted to reach different MFR and molecularweight (Mw by GPC) values, as shown in Table 6.

TABLE 5 Catalysts used for the production of Slurry-polymerizedPolypropylenes Example Ligand Activator SL1 1 B1 SL2 1 B1 SL3 1 B1 SL4 1B1 SL5 4 B1 SL6 4 B1 Catalysts: 1 =(rac-dimethylsilyl)bis(2-methyl-4-phenylindenyl)zirconium dimethyl, 4 =(rac-dimethylsilyl)bis(2-methyl-4-(3,′5′-di-tert-butylphenyl)indenyl)zirconiumdimethyl. Activator: B1 =dimethylaniliniumtertrakis(pentafluorophenyl)borate.All catalysts supported on silica; Triethylaluminum (TEAL) used asimpurity scavenger.

TABLE 6 Slurry product properties for unmodified reactor granulesNominal GPC (DRI) DSC data (second heating) MFR Mw Tmp Tcp Tmp − Tcp SCLExample g/10 min (kg/mol) (° C.) (° C.) (° C.) (° C.) ACHIEVE 30 162.1148.4 108.1 40.3 35.0 1605 ACHIEVE 23 N/A 148.3 104.9 43.4 34.9 3854ACHIEVE 23 N/A 148.0 106.1 41.9 34.6 3854 ACHIEVE 400 105.2 151.2 111.739.5 37.5 6025G1 SL1 150 117.3 151.4 110.6 40.8 37.7 SL2 40 162.6 151.8110.5 41.3 38.0 SL3 214 107.5 151.6 111.9 39.7 37.9 SL4 240 106.3 151.8110.2 41.6 38.0 SL5 5 239.5 157.6 115.0 42.6 43.3 SL6 100 129.1 157.1113.6 43.5 42.8 Supercooling Limit (SCL) derived by SCL = 0.907x −99.64, where x is Tmp.

Examples SL5 and SL6 were polymerized in a bulk liquid-phase pilot line,involving two continuous, stirred-tank reactors, operated in series. Thereactors were equipped with jackets for removing the heat ofpolymerization. The catalyst, described in Table 5 above, was fed as a20% solution in mineral oil and flushed into the lead reactor usingpropylene. Key process settings employed for the polymerization ofExamples SL 5 and SL6 are described in Table 7.

TABLE 7 Process Parameters for Polymerization of Examples SL5 and SL6Example SL5 Example SL6 Catalyst feed rate (g/hr) 4.9 3.4 Scavenger(TEAL) feed rate (ml/min) 4.6 4.5 (2 wt % in hexane) Lead reactortemperature (° C.) 74 74 Lead reactor pressure (psig) 471.6 474.6 Leadreactor C₃ feed (kg/hr) 79.5 79.6 Lead reactor H₂ gas concn (mppm) 11562986 Tail reactor temperature (° C.) 68 68 Tail reactor pressure (psig)421.7 421.2 Tail reactor C₃ feed (kg/hr) 29.5 29.5 Tail reactor H₂ gasconcn (mppm) 1314 3613 Lead reactor production rate (kg/hr) 28.5 22.7Tail reactor production rate (kg/hr) 10.7 11.8 Total production rate(kg/hr) 39.1 34.5 Lead reactor residence time (hr) 2.56 2.85 Tailreactor residence time (hr) 1.87 1.86 Total residence time (hr) 4.4 4.7Polymer was discharged from the reactors as granular product. Keycharacterization data on the reactor granules of Examples SL5 and SL6are shown in Table 6.Disclosure Ethylene-propylene (EP) Copolymer Synthesis Examples UsingContinuous Stirred Tank Reactor (CSTR)

All polymerizations were performed in bulk polymerization systems (i.e.,without using solvent, except for what was introduced with the catalystsolution, which did not exceed 10 wt %) and without monomer recycle.

Propylene Grade 2.5 (Airgas, Piscataway, N.J.) was obtained in #100 lowpressure cylinders equipped with dip leg for liquid delivery to themonomer blending station. Ethylene Grade 4.5 (Airgas, Piscataway, N.J.)was obtained in high-pressure cylinders.

Custom blends containing ethylene and propylene were prepared in house.The monomer blend was fed to the reactor from the monomer blend vessel.

Gas samples were analyzed using a HP6890N (Agilent Technologies) gaschromatograph (GC) equipped with flame ionization detector (FID), gassampling valve, and pressure control compensation. The analysis wasperformed with a 30 m 0.53 mm ID HP AL/M megabore capillary column (filmthickness 15 micron). The carrier gas was helium. The temperatureprogram started at 70° C., held initially for 3 min, ramped to 150° C.at 20° C./min. Total analysis time was 7 minutes. The data were acquiredand processed by ChromPerfect software (Justice Laboratory Software).Calibration standards containing ethylene, propane and propylene werepurchased from DCG Partnership, Pearland, Tex. The FID response factorswere based on these calibration standards and were also checked againstthe results published by J. T. Scanlon, D. E. Willis in J. Chrom. Sci.23 (1985) 333 and by W. A. Dietz in J. Gas Chrom. (1967) 68. For ourmass balance calculations, propane, a trace impurity in the propylenefeed (Air Gas), served as internal standard.

The monomer blend feed was purified using two separate beds in series:activated copper (reduced in flowing H₂ at 225° C. and 1 bar) for O₂removal, and molecular sieve (5 Å, activated in flowing N₂ at 270° C.)for water removal. The flow rate and density of the feed were measuredby a Coriolis mass flow meter (Model PROline promass 80, Endress andHauser) that was located downstream of the purification traps on thelow-pressure side of the feed pump. The purified monomer blend was fedby a diaphragm pump (Model MhS 600/11, ProMinent Orlita, Germany).

For effluent gas sampling, a laboratory gas pump (Senior Metal Bellows,Model MB-21) was used to continually remove a gas stream from theproduct collection vessel. This stream of reactor effluent was sent tothe GC gas sampling port and through the GC sampling loop. The GC wasprogrammed to acquire a new sample every 10 minutes during the run. Theoff-line feed and on-line effluent analysis results provided thecompositional input for the mass balance calculations. The total feedmass flow was generated by summing the monomer feed flow rate measuredby the mass-flow meter and the catalyst flow rate measured by the weightdrop in the catalyst feed vessel.

Catalyst solutions were prepared in an Ar-filled glove box by usingtoluene stock solutions of the catalyst precursor and the activator, andwere delivered to the reactor by a continuous high-pressure syringe pump(PDC Machines, Inc., Warminster, Pa.). The pump rate directly affordedthe catalyst solution feed rate for the mass balances.

Material balances were calculated from two independent composition datasets. One of them relied on effluent gas analysis and propane internalstandard. The other one was based on product yield and ¹³C NMR and IRcompositional analyses of the product polymer. The on-line analysisprovided conversion, yield, and product composition data, thereforeallowed to monitor and control those process parameters.

Tables 7 and 8 below provide examples for process conditions applied andproduct compositions obtained by processes of the current disclosure.

TABLE 7 Exemplary process conditions for producing ethylene-propylenerandom copolymers of about 20 g/10 min MFR and 14-15 wt % ethylenecontent by disclosure processes Sample number 25230- 25231-Process/Product Variable Unit 124 149 059 087 Average Reactortemperature deg C. 105 106 106 104 105 Reactor pressure psi 10278 1043610467 10190 10343 Feed ethylene (E/(E + P)) wt % 7.2 7.1 6.6 6.3 6.8Propylene conversion % 19 20 19.2 19 19 Ethylene conversion % 41 46 48.547 46 Reactor ethylene (E/(E + P)) wt % 4.4 4.2 3.7 3.8 4.0 Productethylene wt % 14.3 15.1 15.1 14.4 14.7 Inert solvent/diluent wt % 5.63.9 5.4 6.1 5.3 Residence time min 5.0 5.0 5.5 5.4 5.2 Ethyleneincorporation ratio (Prod. E/P)/(rxn E/P) 3.6 4.1 4.6 4.3 4.1 MFR g/10min 19 19 21 18 19 Mw kg/mol 130 123 125.6 131 127 Mn kg/mol 64 61 61.966 63

TABLE 8 Exemplary process conditions for producing ethylene-propylenerandom copolymers of about 9-16 g/10 min MFR and 11-12 wt % ethylenecontent by disclosure processes Sample # 25231- Process/Product VariableUnit 111 116 Reactor temperature deg C. 97 96 Reactor pressure psig10285 10805 Feed ethylene (E/(E + P)) wt % 5.2 4.9 Propylene conversion% 14.2 17.9 Ethylene conversion % 35.5 43.2 Reactor ethylene (E/(E + P))wt % 3.6 3.1 Product ethylene wt % 11.9 11.1 Inert solvent/diluent wt %6.9 4.9 Residence time min 5.1 5.1 Ethylene incorporation ratio (Prod.E/P)/ 3.6 3.9 (rxn E/P) MFR g/10 min 16 9 Mw kg/mol 150 167 Mn kg/mol 7484

The products obtained by the bulk homogeneous process disclosed hereinwere compared with a comparative product made with the same catalyst viaa solution polymerization process (designated COM1). The catalystprecursor used was dimethyl(μ-dimethylsilyl)bis(indenyl)hafnium and thecatalyst activator used wasdimethylaniliniumtetrakis(heptafluoronaphthyl)borate. The comparativeCOM1 product and the products made by the inventive process disclosedherein were selected to have the same MFR and ethylene content. Themicrostructural differences between COM1 made by the comparativesolution process and products of similar (15 wt %) ethyleneconcentration and MFR (about 20 g/min) made by the inventive processesdisclosed herein (designated samples 25230-124 and 25230-149) areillustrated in Table 9 below.

TABLE 9 A comparison of the microstructure and randomness of prior artand current disclosure ethylene-propylene copolymer products of ~15 wt %ethylene and ~20 g/10 mn MFR Ethylene Propylene Monomer sequence contentsequence regio defects distribution by NMR Total 2,1-E 2,1-EE 2,1-P EEEEEP PEP EPE PPE PPP Cluster Sample # wt % mol % mol % mol fraction IndexR_(E) · R_(P) 25230-124* 15.5 21.6 0.97 0.56 0.41 0.00 0.007 0.060 0.1490.052 0.250 0.482 9.79 0.76 25230-149** 14.9 20.8 1.05 0.55 0.51 0.000.007 0.058 0.143 0.052 0.255 0.486 9.77 0.77 COM1 13.9 19.5 0.63 0.390.24 0.00 0.009 0.051 0.135 0.045 0.238 0.522 9.81 0.84 *Average of twoNMR tests *Average of four NMR tests

As it is demonstrated in Table 9, both the comparative and the inventiveproducts contain randomly distributed ethylene in the polymer chains:the Cluster Indices are essentially equal to 10 and the R_(E)·R_(P)products are near 1.0. Unexpectedly, however, the total regio defects inthe continuous propylene segments in the polymer chains aresubstantially different, namely, the total regio defects in theethylene-propylene random copolymers made by the inventive processesdisclosed herein are 54% and 67% higher for the 25230-124 and 25230-149samples, respectively, than that in the comparative product (COM1) madeby the solution process with the same ethylene content and MFR.

Regio Defect Concentrations by ¹³C NMR

Carbon NMR spectroscopy was used to measure stereo and regio defectconcentrations in the polypropylene. Carbon NMR spectra were acquiredwith a 10-mm broadband probe on a Varian UnityPlus 500 spectrometer. Thesamples were prepared in 1,1,2,2-tetrachloroethane-d₂ (TCE). Samplepreparation (polymer dissolution) was performed at 140° C. In order tooptimize chemical shift resolution, the samples were prepared withoutchromium acetylacetonate relaxation agent. Signal-to-noise was enhancedby acquiring the spectra with nuclear Overhauser enhancement for 6seconds before the acquisition pulse. The 3.2 second acquisition periodwas followed by an additional delay of 5 seconds, for an aggregate pulserepetition delay of 14 seconds. Free induction decays of 3400-4400coadded transients were acquired at a temperature of 120° C. AfterFourier transformation (256 K points and 0.3 Hz exponential linebroadening), the spectrum is referenced by setting the dominant mmmmmeso methyl resonance to 21.83 ppm.

Chemical shift assignments for the stereo defects (given as stereopentads) can be found in the literature [L. Resconi, L. Cavallo, A.Fait, and F. Piemontesi, Chem. Rev. 2000, 100, pages 1253-1345]. Thestereo pentads (e.g. mmmm, mmmr, mrrm, etc.) can be summed appropriatelyto give a stereo triad distribution (mm, mr, and rr), and the molepercentage of stereo diads (m and r). Three types of regio defects werequantified: 2,1-erythro, 2,1-threo, and 3,1-isomerization. Thestructures and peak assignments for these are also given in thereference by Resconi. The concentrations for all defects are quoted interms of defects per 10,000 monomer units.

The regio defects each give rise to multiple peaks in the carbon NMRspectrum, and these are all integrated and averaged (to the extent thatthey are resolved from other peaks in the spectrum), to improve themeasurement accuracy. The chemical shift offsets of the resolvableresonances used in the analysis are tabulated below. The precise peakpositions may shift as a function of NMR solvent choice.

Regio defect Chemical shift range (ppm) 2,1-erythro 42.3, 38.6, 36.0,35.9, 31.5, 30.6, 17.6, 17.2 2,1-threo 43.4, 38.9, 35.6, 34.7, 32.5,31.2, 15.4, 15.0 3,1 insertion 37.6, 30.9, 27.7

The average integral for each defect is divided by the integral for oneof the main propylene signals (CH₃, CH, CH₂), and multiplied by 10000 todetermine the defect concentration per 10000 monomers.

Differential Scanning Calorimetry for Measuring Crystallization andMelting Temperatures (Tcp and Tmp) and Heat of Fusion (ΔHf):

Peak crystallization temperature (Tcp), Peak melting temperature (Tmp)and heat of fusion (Hf, or ΔHf) were measured using DifferentialScanning Calorimetry (DSC) on reactor samples (with no nucleating agentadded). This analysis was conducted using either a TA Instruments MDSC2920 or a Q2000 Tzero DSC. The DSC was calibrated for temperature usingfour standards (Tin, Indium, cyclohexane, and water). Heat of fusion ofIndium (28.46 J/g) was used to calibrate the heat flow signal. Thereproducibility of peak melting temperature for polypropylene is within±0.3° C. and heat of fusion is within 2%. Typically about 3 to 5 mg ofpolymer from the reactor was sealed in a standard aluminum pan with flatlids and loaded into the instrument at room temperature. Sample wascooled to −70° C. and heated at 10° C./min to 210° C. to acquire themelting data (first heat). This first heating provides the meltingbehavior for samples made in the reactor. Since thermal historyinfluences melting and crystallization behavior, the sample was held for5 minutes at 210° C. to destroy its thermal history. This was followedby cooling this sample to −70° C. at a cooling rate of 10° C./min toanalyze its crystallization behavior at this cooling rate. Theexothermic peak of crystallization was analyzed using the softwareprovided by the vendor and the peak of crystallization (Tcp) isreported. The sample was held at this low temperature of −70° C. forabout 10 minutes to equilibrate it and then heated back to 210° C. at10° C./min to analyze the melting behavior (second heat). This gave themelting behavior of samples crystallized under controlled coolingconditions (10° C./min). The melting temperature reported is obtained bythe analysis of the melting peak using the software provided by thevendor and corresponds to the peak of the melting transition (Tmp). Allsamples reported in this work showed relatively narrow, single meltingpeaks and the breadth of melting did not show any significant change fordifferent catalysts. Area under the melting curve was used to determinethe heat of fusion (ΔH_(f)) in J/g using the software provided by thevendor. This heat of fusion is used to calculate the degree ofcrystallinity. The percent crystallinity is calculated using theformula: percent crystallinity=[area under the curve (J/g)/207.14(J/g)]×100%. A value of 207.14 J/g or 8700 J/mol is the equilibrium heatof fusion for 100% crystalline polypropylene and is obtained from Ref:B. Wunderlich in “Thermal Analysis” Academic Press, page 418, 1990.

Melt-Flow Rate Measurements:

The Melt-Flow Rates (MFR) of polymers were determined by using DyniscoKayeness Polymer Test Systems Series 4003 apparatus following the methoddescribed in the Series 4000 Melt Indexer Operation manual, Method B.The method follows ASTM D-1238, Condition L, 2.16 kg and 230° C. Allsamples were stabilized by using Irganox 1010.

Molecular Weights (Mw, Mn and Mz) by Gel-Permeation Chromatography(GPC):

Molecular weight distributions were characterized using Gel-PermeationChromatography (GPC), also referred to as Size-Exclusion Chromatography(SEC). Molecular weight (weight average molecular weight, Mw, numberaverage molecular weight Mn, Viscosity average molecular weight, Mv, andZ average molecular weight, Mz) were determined using High-TemperatureGel-Permeation Chromatography equipped with a differential refractiveindex detector (DRI) to measure polymer concentrations (either fromWaters Corporation with on-line Wyatt DAWN “EOS” and Waters GPCVviscometer detectors, or Polymer Laboratories with on-line Wyattmini-DAWN and Viscotek Corporation viscometer detectors. Experimentaldetails on the measurement procedure are described in the literature byT. Sun, P. Brant, R. R. Chance, and W. W. Graessley, Macromolecules,Volume 34, Number 19, 6812-6820 (2001).

The analysis was performed using a Waters GPCV 2000 (Gel PermeationChromatograph) with triple detection. The three detectors were in serieswith Wyatt DAWN “EOS” MALLS 18 angle laser light scattering detectorfirst, followed by the DRI (Differential Refractive Index) thenDifferential Viscometer detector. The detector output signals arecollected on Wyatt's ASTRA software and analyzed using a GPC analysisprogram. The detailed GPC conditions are listed in Table 8 below.

Standards and samples were prepared in inhibited TCB(1,2,4-trichlorobenzene) solvent. Four NBS polyethylene standards wereused for calibrating the GPC. Standard identifications are listed in thetable below. The samples were accurately weighed and diluted to a ˜1.5mg/mL concentration and recorded. The standards and samples were placedon a PL Labs 260 Heater/Shaker at 160° C. for two hours. These werefiltered through a 0.45 micron steel filter cup then analyzed.

The concentration, c, at each point in the chromatogram is calculatedfrom the baseline-subtracted DRI signal, IDRI, using the followingequation:c=KDRI IDRI/(dn/dc)where KDRI is a constant determined by calibrating the DRI, and (dn/dc)is the same as described below for the LS analysis. Units on parametersthroughout this description of the SEC method are such thatconcentration is expressed in g/cm³, molecular weight is expressed ing/mole, and intrinsic viscosity is expressed in dL/g.

For the light-scattering detector used at high temperature, the polymermolecular weight, M, at each point in the chromatogram is determined byanalyzing the LS output using the Zimm model for static light scattering(M. B. Huglin, Light Scattering from Polymer Solutions, Academic Press,1971):

$\frac{K_{o}c}{\Delta\;{R(\theta)}} = {\frac{1}{{MP}(\theta)} + {2\; A_{c}c}}$Here, ΔR(θ) is the measured excess Rayleigh scattering intensity atscattering angle θ, c is the polymer concentration determined from theDRI analysis, A2 is the second virial coefficient, P(θ) is the formfactor for a monodisperse random coil (described in the abovereference), and Ko is the optical constant for the system:

$K_{o} = \frac{4\;\pi^{2}{n^{2}( {{dn}/{dc}} )}^{2}}{\lambda^{4}N_{A}}$in which NA is Avogadro's number, and (dn/dc) is the refractive indexincrement for the system. The refractive index, n=1.500 for TCB at 135°C. and λ=690 nm. In addition, A2=0.0006 for propylene polymers and0.0015 for butene polymers, and (dn/dc)=0.104 for propylene polymers and0.098 for butene polymers.

A high temperature Viscotek Corporation viscometer was used, which hasfour capillaries arranged in a Wheatstone bridge configuration with twopressure transducers. One transducer measures the total pressure dropacross the detector, and the other, positioned between the two sides ofthe bridge, measures a differential pressure. The specific viscosity,η_(s), for the solution flowing through the viscometer is calculatedfrom their outputs. The intrinsic viscosity, [η]_(i), at each point inthe chromatogram is calculated from the following equation:[η]_(i)=η_(si) /C _(i)where the concentration, C_(i), was determined from the DRI output.

The branching index (g′) is calculated using the output of theSEC-DRI-LS-VIS method as follows. The branching index g′ is defined as:Sample measured [η]/calculated theoretical [η] of a linear polymer,where the calculated theoretical [η] of a linear=k M^(α)

where k=0.0002288 and α=0.705 for propylene polymers.

Mv is the viscosity average molecular weight based on molecular weightsdetermined by light-scattering (LS) analysis. The viscosity averagemolecular weight, Mv, of the sample is calculated by:Mv={Σh _(i) M _(i) ^(α) /Σh _(i)}^(1/α)M_(i=)molecular weight for each time slice, h_(i), from thechromatogram, and the summations are carried out over allchromotographic slices, i.e., between the integration limits.

TABLE 8 Gel Permeation Chromatography (GPC) measurement conditionsINSTRUMENT WATERS 2000 V + Wyatt Dawn EOS COLUMN Type: 3 × MIXED BEDTYPE “B” 10 MICRON PD (high porosity col.'s) Length: 300 mm ID: 7.8 mmSupplier POLYMER LABS SOLVENT PROGRAM A 0.54 ml/min TCB inhibited GPCconsole setting was 0.5 mL/min to which 8% expansion factor (fromWaters) makes actual flow 0.54 mL/min DETECTOR A: Wyatt MALLS 17 angle'sof laser light scattering detector B: DIFFERENTIAL REFRACTIVE INDEX(DRI) in series C: Viscometer IDvol. = +232.2 ul LS to DRI IDvol. =−91.8 ul Dp to DRI TEMPERATURE Injector: 135° C. Detector: 135° C.Column: 135° C. DISOLUTION Shaken for 2 h on a PL SP260 heaterCONDITIONS Shaker @ 160° C. SAMPLE FILTRATION Through a 0.45μ SS Filter@ 135° C. INJECTION VOLUME 329.5 μL SAMPLE 0.15 w/v % (1.5 mg/ml) Targetwt CONCENTRATION SOLVENT DILUENT TCB inhibited CALIBRATION NIST 1482a;NIST 1483a; NIST 1484a NARROW PE STANDARDS BROAD PE NIST 1475a STANDARDMonomer Sequence Distribution and Composition by ¹³C NMR:

Carbon NMR spectroscopy was used to measure monomer sequencedistribution, composition, clustering, and regio defect concentrationsin the propylene sequences. Carbon NMR spectra were acquired with a10-mm broadband probe on a Varian UnityPlus 500 spectrometer. Thesamples were prepared in 1,1,2,2-tetrachloroethane-d₂ (TCE). Samplepreparation (polymer dissolution) was performed at 140° C. In order tooptimize chemical shift resolution, the samples were prepared withoutchromium acetylacetonate relaxation agent. Signal-to-noise was enhancedby acquiring the spectra with nuclear Overhauser enhancement for 10seconds before the acquisition pulse. The 3.2 second acquisition periodwas followed by an additional delay of 4 seconds, for an aggregate pulserepetition delay of 17 seconds. Free induction decays of 3400-4400coadded transients were acquired at a temperature of 120° C. AfterFourier transformation (256K points and 0.3 Hz exponential linebroadening), the spectrum is referenced by setting the upfield peak ofthe TCE to 74.054 ppm. FIG. 25 depicts a typical ¹³C NMR spectrum of aC₂ ⁼-C₃ ⁼ copolymer with high ethylene content.

The Journal of Applied Polymer Science article by Di Martino andKelchtermans (J. Applied Polymer Sci. 56 (1995) 1781) provides anaccessible tabulation of the chemical shift assignments for the peaks inthe spectrum. The review article by Randall and Rucker (J. C. Randalland S. P. Rucker, Macromolecules 27(8) (1994) 2120) gives an overview ofthe procedure for converting the peak areas to the monomer sequencetriads that define the chain microstructure. The measured integrals areconverted into monomer triad and chain defect concentrations through alinear algebraic matrix system y=Ax which relates the two. The matrixsystem employs the integrals as the dependent y vector, the triad/defectconcentrations as the x vector, and the number of carbons (intensity)contributed by each triad or defect structure to each integral region asthe transfer matrix, A. The nomenclature adopted for the analysis istabulated below:

Chemical shift range (ppm) NMR region Chain structure 45-48 A PPP + ½PPE  43-43.8 2,1-P 2,1-Pt 41-42 2,1-P 2,1-Pe 37-39 B PEP + (½)PEE + EPE +(½)PPE  38.4-38.95 2,1-P 2,1-Pe + 2,1-Pt 35.2-36   2,1-P 2,1-Pe + 2,1-Pt  34-35.7 2,1-E + 2,1-P 2,1-E + 2,1-EE + 2,1-Pt 33.8, 33.9 2,1-E 2,1-E 33.4, 33.55 2,1-EE 2,1-EE 32.9-33.4 C EPE   32-32.5 2,1-P 2,1-Pt 31.1-31.25 2,1E + 2,1-EE 2,1-E, 2,1-EE  30.5-31.05 D EPP + 2,1-Pt +2,1-Pe 30.6-30.7 Γγ PEEP 30.2-30.3 γδ⁺ PEEE + 2,1-Pe 29.8-30   δ⁺δ⁺(EEE)n 27.8-29   F PPP 27.5-27.9 Bγ 2,1-E-E 27.25-27.45 G1 PEE 26.9-27.25 G2 PEE 24.2-24.9 H PEP 21.2-22.3 I1 PPPmm 20.5-21.2 I2PPPmr + PPE 19.76-20.3  I3 PPPrr + EPE 15.0 2,1-P-t 2,1-P-t 15.4 2,1-P-t2,1-P-t 17.2 2,1-P-e 2,1-P-e 17.5 2,1-P-e 2,1-P-e

The ethylene and propylene triad concentrations are normalized to 100%.The mole-percent ethylene will then be the sum of the ethylene-centeredtriads, and mole-percent propylene will be the sum of thepropylene-centered triads. The defect concentrations can be cast interms of mol % defects, i.e. defects per 100 triads.

The distribution of monomers in the chain can be modeled with astatistical model for the polymerization. The simplest, Bernoullian,model assumes that comonomers add to the growing chain without bias fromthe monomer currently at the chain terminus. The next-higher ordermodel, the first-order Markovian, assumes that the monomer is sensitiveto the current chain-end monomer during the addition reaction. Thisallows the mathematical description of a reaction system's propensityfor making alternating, random, and block copolymers. The Markoviananalysis of finite EP polymer chains by Randall and Rucker (J. C.Randall and S. P. Rucker, Macromolecules 27(8) (1994) 2120) explains themathematics behind the statistical modeling of the polymermicrostructure, and is excerpted in part here.

There are four basic first-order Markov transition probabilities for thefour possible adjoining pairs of monomer units In a Markov diad, thefirst unit is called the initial state and the second unit is called thefinal state. With the exception of the end groups, a diad descriptionrequires that each unit in a copolymer chain serves as both an initialstate and a final state. For a copolymer chain, there are only twopossibilities for the initial state and, likewise, only twopossibilities for the final state. The statistical treatment that followwill be derived for a poly(ethylene-co-propylene), but they apply to anycopolymer chain.

Probability designations for ethylene-propylene copolymerization

Initial State Add Final state Transition probability E E E P_(EE) E P PP_(EP) P E E P_(PE) P P P P_(PP)

Accordingly, the four transition probabilities outlined in the tableabove must be related as follows:P _(EE) +P _(EP)=1P _(PE) +P _(PP)=1

A first order Markovian system reduces to Bernoullian whenP _(EE) =P _(PE) =P _(E)=mole fraction of “E”, andP _(EP) =P _(PP) =P _(P)=mole fraction of “P”,which demonstrates that chain propagation for Bernoullian copolymersystems is independent of the identity of the initial state.Consequently, Bernoullian statistical analyses are defined with only oneindependent variable and first order Markov analyses are defined withtwo independent variables. The process for deriving the transitionprobabilities from the triad concentrations is described comprehensivelyin the work of Randall and Rucker (J. C. Randall and S. P. Rucker,Macromolecules 27(8) (1994) 2120). A sequence of any length in acopolymer chain can now be defined in terms of only two transitionprobabilities.

Calculating the transition probabilities has utility not only forcalculating the predicted concentration of any arbitrary sequence ofmonomers in the chain, but also for characterizing the propensity of themonomers to cluster in the chain. One such method for characterizing thetendency of comonomers to polymerize in a non-random fashion is thecluster index developed by Randall (J. C. Randall, “A Review of HighResolution Liquid ¹³Carbon Nuclear Magnetic Resonance Characterizationsof Ethylene-Based Polymers”, JMS-Rev. Macromol. Chem. Phys. (1989),C29(2 & 3), pp 201-317). This measures the deviation in theconcentration of isolated comonomer triads (EPE triads) from thatpredicted by a Bernoullian model:

${{Cluster}{\mspace{11mu}\;}{index}} = {10 \cdot \lbrack {1 - \frac{\lbrack{EPE}\rbrack_{observed} - \lbrack{EPE}\rbrack_{random}}{\lbrack P\rbrack_{observed} - \lbrack{EPE}\rbrack_{random}}} \rbrack}$

-   -   which can be restated in terms of the monomer triads:

${{Cluster}{\mspace{11mu}\;}{index}} = {10 \cdot \lbrack {1 - \frac{\lbrack{EPE}\rbrack_{observed} - \lbrack{EPE}\rbrack_{random}}{\begin{matrix}{\lbrack{PPP}\rbrack_{observed} + \lbrack {{PPE} + {EPP}} \rbrack_{observed} +} \\{\lbrack{EPE}\rbrack_{observed} - \lbrack{EPE}\rbrack_{random}}\end{matrix}}} \rbrack}$

In a polymer of 50 mol % ethylene, for example, an alternatingarchitecture will have all the P comonomer in one-monomer blocks. Thus[EPE]_(observed)=[P]_(observed), and the cluster index becomes 0. Arandom copolymer will have [EPE]_(observed)=[EPE]_(random), giving acluster index of 10. In the case of a block copolymer, the fraction inthe brackets becomes −0.33, and the cluster index 13.3. This issummarized in the table below:

Cluster index for 50/50 Microstructure copolymer Alternating 0 Random 10Block 13.3

Another pair of common descriptors for the polymerization process arethe reactivity ratios, R_(E) and R_(P), which can be expressed as rateof homopolymerization divided by the rate of copolymerization,multiplied or divided by the ratio [E]/[P].

$R_{E} = {\frac{k_{EE}}{k_{EP}} = \frac{P_{EE}\lbrack P\rbrack}{P_{EP}\lbrack E\rbrack}}$$R_{P} = {\frac{k_{PP}}{k_{PE}} = \frac{P_{PP}\lbrack E\rbrack}{P_{PE}\lbrack P\rbrack}}$

Calculating these reactivity ratios from the NMR data would requireinformation about the monomer ratios in the reactor, [E]/[P], whichoften are not available. Multiplying these quantities R_(E) and R_(P),we can remove the monomer ratio dependence:

${R_{E}R_{P}} = \frac{P_{EE}P_{PP}}{P_{EP}P_{PE}}$

In principle, this product can be determined from any polymer analyticaltechnique that yields a triad distribution and also from kineticsexperiments. The important result of this calculation is that there arecertain values for the transition probabilities that provide breakpoints for describing blocky, alternating, or random polymers, and theseare tabulated below.

Transition probabilities R_(E)R_(P) Polymer structure P_(EE) = 1 P_(EP)= 0 ∞ blocky P_(PP) = 1 P_(PE) = 0 P_(EE) = .5 P_(EP) = .5 1 randomP_(PP) = .5 P_(PE) = .5 P_(EE) = 0 P_(EP) = 1 0 perfectly alternatingP_(PP) = 0 P_(PE) = 1

Several regio defects were assigned and integrated in the NMR spectrumwhere observed. These result from reverse (2,1) addition of thepropylene monomer, followed by either a propylene, one ethylene, or twoethylenes, and are designated 2,1-P, 2,1-E, and 2,1-EE, respectively.Peak assignments for these defects can be found in the work of Cheng.(H. N. Cheng, “¹³C NMR Analysis of Ethylene-Propylene Rubbers”,Macromolecules, 17, 1950-1955, (1984)). The defects are illustrated inFIG. 26 for a polymer chain segment growing from left to right.

The quantification of the regio defect concentrations can be performedby integrating representative spectral region(s) for each defect, andcomparing that (average) integral against the total monomer triad count,as determined from the linear algebraic solution described above.

For the materials considered here, we used the 33.8-33.9 ppm region toquantify 2,1-E defects, and the 33.4-33.55 region to quantify the 2,1-EEdefect. The 2,1-P defects when present give characteristic (andwell-resolved) peaks in the 15-17.5 ppm region). These are furtherresolved into contributions from erythro (2,1-Pe) and threo (2,1-Pt)stereochemistry at the defect site.

Ethylene Concentration by Infrared Spectroscopy (IR):

Ethylene analyses of ethylene-propylene copolymers by IR were performedusing thin polymer films of the product EP copolymers. The calibrationstandards and test films were prepared according to sub-method A of ASTMD3900. The calibration correlated the area ratio of the peaks at 1155and 722 cm⁻¹, and was fitted by the following expression for productswith ethylene contents of less than 40 wt %:Ethylene wt %=72.698−86.495 X+13.696 X ²where X=(peak area at 1155 cm⁻¹)/(peak area at 722 cm⁻¹).

The ¹³C NMR and IR analysis results showed good agreements and the IRand NMR results were typically within 1 wt %.

Polymer Density:

Density is measured by density-gradient column, such as described inASTM D1505, on a compression-molded specimen that has been slowly cooledto room temperature.

Quiescent Isothermal Crystallization Kinetics Of SupercriticalPolypropylenes

The crystallization kinetics of the SC-PP were measured via isothermalmeasurements using a Perkin Elmer Diamond DSC. The DSC cell wascalibrated for temperature using two standards: indium (onset of secondmelting peak used is 156.6° C.) and deionizer water (onset of firstmelting peak used is 0° C.). Heat of fusion was calibrated usingstandard heat of fusion of Indium 28.46 J/g. Reproducibility of Indiumfor a calibrated DSC cell for onset of melting is ±0.2° C. and heat offusion is ±1-2%.

About 3-4 mg of a sample was encapsulated in a Aluminum pan provided bythe vendor. Reference pan of closely matching mass was used for allmeasurements. Sample was equilibrated at room temperature and heated to210° C. at 10° C./min followed by a hold at 210° C. for 3 minutes todestroy its thermal history. It was then rapidly cooled at programmedcooling rate of 300° C./min to the desired isothermal temperature andheld isothermally for 30 minutes to allow the sample to crystallizeisothermally. The start temperature of the isothermal measurement variedfrom sample to sample but typically for samples that had a peak meltingtemperature between 150° C. to 156° C. at heating rate of 10° C./min,the start temperature for isothermal measurement ranged between 132° C.to 136° C. For samples that have a lower melting temperature, theisothermal measurement was started at a slightly lower temperature.After the isothermal crystallization for 30 minutes the sample washeated back to 210° C. at a heating rate of 10° C./min to record themelting characteristics of the isothermally crystallized sample. Thesame sample was held at 210° C. for 3 minutes and cooled to atemperature 2 degree lower than the start temperature at 300° C./minfollowed by a 30 minutes hold and then the heating segment. With eachsample, this cool, isothermal hold followed by heating cycle wasrepeated for a total of 5 temperatures at a maximum and a fresh sampleused to extend the measurement range to lower temperatures. Isothermalcrystallization and melting data was collected for at least about 8-10temperatures for each polypropylene sample.

Data analysis was performed using a Pyris data analysis software(version 7.0) provided by Perkin Elmer. Time taken for crystallinity todevelop at each isothermal crystallization temperature was evaluated byintegrating the exothermic heat of crystallization (in J/g) versus time(minutes). From a table of % crystallized versus time, time taken for50% crystallinity to develop was noted as the t-half time in minutes atthat particular temperature. Time taken for 50% crystallinity isreported at 122° C. and 126° C. for comparison of crystallizationkinetics of different polypropylenes. In addition, t-half data atadditional temperatures covering a temperature range about 15 to 20degrees are plotted in the Figure versus crystallization temperature tocompare the crystallization behavior. Lower t-half time at a particularcrystallization temperature is indicative of faster crystallization.

Mechanical Property Test Methods:

Tensile Properties ASTM D 638 Heat Deflection Temperature ASTM D 648 (66psi) Vicat Softening Temperature ASTM D 1525 (200 g) Gardner ImpactStrength ASTM D 5420 Izod Impact Strength ASTM D 256 (A) 1% SecantFlexural Modulus ASTM D 790 (A) Rockwell Hardness ASTM D 785 (R scale)

Applicants have attempted to disclose all embodiments and applicationsof the disclosed subject matter that could be reasonably foreseen.However, there may be unforeseeable, insubstantial modifications thatremain as equivalents. While the present invention has been described inconjunction with specific, exemplary embodiments thereof, it is evidentthat many alterations, modifications, and variations will be apparent tothose skilled in the art in light of the foregoing description withoutdeparting from the spirit or scope of the present disclosure.Accordingly, the present disclosure is intended to embrace all suchalterations, modifications, and variations of the above detaileddescription.

All patents, test procedures, and other documents cited herein,including priority documents, are fully incorporated by reference to theextent such disclosure is not inconsistent with this invention and forall jurisdictions in which such incorporation is permitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.All numerical values within the detailed description and the claimsherein are “about” or “approximately” the indicated value, and take intoaccount experimental error and variations that would be expected by aperson having ordinary skill in the art.

What is claimed is:
 1. A blend of isotactic polypropylene andethylene-propylene copolymer comprising: between 1 and 50 wt % ofisotactic polypropylene with a weight average molecular weight (Mw) ofat least 35 kg/mol, and between 50 and 99 wt % of ethylene-propylenecopolymer including between 10 wt % and 20 wt % randomly distributedethylene with a melt flow rate (as measured by ASTM D-1238, Condition L,2.16 kg and 230° C.) of between 0.5 and 20,000 g/10 min, wherein thecopolymer is polymerized by a bulk homogeneous polymerization process,and wherein the total regio defects in the continuous propylene segmentsof the copolymer is between 40 and 150% greater than a copolymer ofequivalent melt flow rate and wt % ethylene polymerized by a solutionpolymerization process, wherein the total regio defects in thecontinuous propylene segments of the copolymer is greater than 0.50 mol%.
 2. The blend of claim 1, wherein the total regio defects in thecontinuous propylene segments of the copolymer is between 40 and 100%greater than a copolymer of equivalent melt flow rate and wt % ethylenepolymerized by a solution polymerization process.
 3. The blend of claim1 wherein the melt flow rate of the copolymer is between 0.5 and 5,000g/10 min.
 4. The blend of claim 1 wherein the total regio defects in thecontinuous propylene segments of the copolymer is greater than 0.70 mol%.
 5. The blend of claim 1 wherein the peak melting temperature of thecopolymer is between 35° and 80° C.
 6. The blend of claim 1, wherein thecopolymer further comprises between 0.5 wt % and 50 wt % of randomlydistributed butene-1, pentene-1, hexene-1, octene-1, decene-1, orcombinations thereof.
 7. The blend of claim 1 wherein the isotacticpolypropylene and ethylene propylene copolymer are both polymerized in abulk homogeneous polymerization process that occurs in two or morereactor trains configured in parallel with a high-pressure separatordownstream fluidly connected to the two or more reactor trains, whereinone or more of the reactor trains produces the isotactic polypropyleneand one or more of the reactor trains produces the ethylene-propylenecopolymer and wherein the high-pressure separator in-line blends theisotactic polypropylene and ethylene-propylene copolymer.
 8. The blendof claim 7, wherein the bulk homogeneous polymerization process for eachreactor train comprises less than 20 wt % of optional solvent.
 9. Theblend of claim 7, wherein at least one of the two or more reactor trainsconfigured in parallel operates above the critical or pseudo-criticaltemperature and the critical or pseudo-critical pressure of itspolymerization system.
 10. The blend of claim 7, wherein the homogeneouspolymerization process utilizes one or more catalyst systems chosen fromZiegler-Natta catalysts, metallocene catalysts, nonmetallocenemetal-centered, heteroaryl ligand catalysts, late transition metalcatalysts, and combinations thereof.
 11. A blend of isotacticpolypropylene and ethylene-propylene copolymer comprising: between 1 and50 wt % of isotactic polypropylene with more than 15 and less than 100regio defects (sum of 2,1-erythro, 2,1-threo insertions, and3,1-isomerizations) per 10,000 propylene units in the polymer chain, anmmmm pentad fraction of 0.85 or more, a weight average molecular weight(Mw) of at least 35 kg/mol, a melting peak temperature of 149° C. orhigher, a heat of fusion (ΔHf) of at least 80 J/g, and wherein thedifference between the DSC peak melting and the peak crystallizationtemperatures (Tmp−Tcp) is less than or equal to 0.907 times the meltingpeak temperature minus 99.64 (Tmp−Tcp≦0.907 Tmp−99.64)° C., and between50 and 99 wt % of ethylene-propylene copolymer including between 10 wt %and 20 wt % randomly distributed ethylene with a melt flow rate (asmeasured by ASTM D-1238, Condition L, 2.16 kg and 230° C.) of between0.5 and 20,000 g/10 min.
 12. The blend of claim 11 wherein the weightaverage molecular weight (Mw) of the isotactic polypropylene is at least75 kg/mol.
 13. The blend of claim 11 wherein the total regio defects inthe continuous propylene segments of the isotactic polypropylene isgreater than 20 and less than 100 regio defects per 10,000 propyleneunits in the polymer chain.
 14. The blend of claim 11 wherein the totalregio defects in the continuous propylene segments of the isotacticpolypropylene is greater than 25 and less than 100 regio defects per10,000 propylene units in the polymer chain.
 15. The blend of claim 11wherein the DSC peak crystallization temperature of the isotacticpolypropylene is greater than 150° C.
 16. The blend of claim 11 whereinthe isotactic polypropylene has a DSC peak melting temperature of 150°C. or higher, and a weight-averaged molecular weight (Mw) of at least125 kg/mol.
 17. The blend of claim 11 wherein the isotacticpolypropylene is polymerized by a bulk homogeneous polymerizationprocess.
 18. The blend of claim 11 wherein the isotactic polypropyleneand ethylene-propylene copolymer are both polymerized in a bulkhomogeneous polymerization process that occurs in two or more reactortrains configured in parallel with a high-pressure separator downstreamfluidly connected to the two or more reactor trains, wherein one or moreof the reactor trains produces the isotactic polypropylene and one ormore of the reactor trains produces the ethylene-propylene copolymer andwherein the high-pressure separator in-line blends the isotacticpolypropylene and ethylene-propylene copolymer.
 19. The blend of claim18, wherein the bulk homogeneous polymerization process for each reactortrain comprises less than 20 wt % of optional solvent.
 20. The blend ofclaim 18, wherein at least one of the two or more reactor trainsconfigured in parallel operates above the critical or pseudo-criticaltemperature and the critical or pseudo-critical pressure of itspolymerization system.
 21. The blend of claim 18, wherein the bulkhomogeneous polymerization process utilizes one or more catalyst systemschosen from Ziegler-Natta catalysts, metallocene catalysts,nonmetallocene metal-centered, heteroaryl ligand catalysts, latetransition metal catalysts, and combinations thereof.
 22. The blend ofclaim 21 wherein the bulk homogeneous polymerization process for theisotactic polypropylene utilizes metallocene catalysts, nonmetallocenemetal-centered, heteroaryl ligand catalysts, late transition metalcatalysts, and combinations thereof.
 23. The blend of claim 22 whereinthe bulk homogeneous polymerization process for the isotacticpolypropylene utilizes a non-coordinating anion activated metallocenecatalyst system.
 24. A blend of polypropylene and ethylene-propylenecopolymer comprising: between 1 and 50 wt % of isotactic polypropylenewith more than 15 and less than 100 regio defects (sum of 2,1-erythro,2,1-threo insertions, and 3,1-isomerizations) per 10,000 propylene unitsin the polymer chain, an mmmm pentad fraction of 0.85 or more, a weightaverage molecular weight (Mw) of at least 35 kg/mol, a melting peaktemperature of 149° C. or higher, a heat of fusion (ΔHf) of at least 80J/g, and wherein the difference between the DSC peak melting and thepeak crystallization temperatures (Tmp−Tcp) is less than or equal to0.907 times the melting peak temperature minus 99.64 (Tmp−Tcp≦0.907Tmp−99.64)° C., and between 50 and 99 wt % of ethylene-propylenecopolymer including between 10 wt % and 20 wt % randomly distributedethylene with a melt flow rate (as measured by ASTM D-1238, Condition L,2.16 kg and 230° C.)of between 0.5 and 20,000 g/10 min, wherein thecopolymer is polymerized by a bulk homogeneous polymerization process,and wherein the total regio defects in the continuous propylene segmentsof the copolymer is between 40 and 150% greater than a copolymer ofequivalent melt flow rate and wt% ethylene polymerized by a solutionpolymerization process.
 25. The blend of claim 24 wherein the weightaverage molecular weight (Mw) of the isotactic polypropylene is at least75 kg/mol.
 26. The blend of claim 24 wherein the total regio defects inthe continuous propylene segments of the isotactic polypropylene isgreater than 20 and less than 100 regio defects per 10,000 propyleneunits in the polymer chain.
 27. The blend of claim 26 wherein the totalregio defects in the continuous propylene segments of the isotacticpolypropylene is greater than 25 and less than 100 regio defects per10,000 propylene units in the polymer chain.
 28. The blend of claim 24wherein the DSC peak crystallization temperature of the isotacticpolypropylene is greater than 150° C.
 29. The blend of claim 24 whereinthe isotactic polypropylene has a DSC peak melting temperature of 150°C. or higher, and a weight-averaged molecular weight (Mw) of at least125 kg/mol.
 30. The blend of claim 24 wherein the total regio defects inthe continuous propylene segments of the copolymer is between 40 and100% greater than a copolymer of equivalent melt flow rate and wt %ethylene polymerized by a solution polymerization process.
 31. The blendof claim 24 wherein the melt flow rate of the copolymer is between 0.5and 5,000 g/10 min.
 32. The blend of claim 24 wherein the total regiodefects in the continuous propylene segments of the copolymer is greaterthan 0.50 mol %.
 33. The blend of claim 24 wherein the total regiodefects in the continuous propylene segments of the copolymer is greaterthan 0.70 mol %.
 34. The blend of claim 24 wherein the peak meltingtemperature of the copolymer is between 35° and 80° C.
 35. The blend ofclaim 24 wherein the copolymer further comprises between 0.5 wt % and 50wt % of randomly distributed butene-1, pentene-1, hexene-1, octene-1,decene-1, or combinations thereof.
 36. The blend of claim 24 wherein theisotactic polypropylene is polymerized by a bulk homogeneouspolymerization process.
 37. The blend of claim 24 wherein the isotacticpolypropylene and ethylene-propylene copolymer are both polymerized in abulk homogeneous polymerization process that occurs in two or morereactor trains configured in parallel with a high-pressure separatordownstream fluidly connected to the two or more reactor trains, whereinone or more of the reactor trains produces the isotactic polypropyleneand one or more of the reactor trains produces the ethylene-propylenecopolymer and wherein the high-pressure separator in-line blends theisotactic polypropylene and ethylene-propylene copolymer.
 38. The blendof claim 37, wherein the bulk homogeneous polymerization process foreach reactor train comprises less than 20 wt % of optional solvent. 39.The blend of claim 37, wherein at least one of the two or more reactortrains configured in parallel operates above the critical orpseudo-critical temperature and the critical or pseudo-critical pressureof its polymerization system.
 40. The blend of claim 37, wherein thebulk homogeneous polymerization process utilizes one or more catalystsystems chosen from Ziegler-Natta catalysts, metallocene catalysts,nonmetallocene metal-centered, heteroaryl ligand catalysts, latetransition metal catalysts, and combinations thereof.
 41. The blend ofclaim 40 wherein the bulk homogeneous polymerization process for theisotactic polypropylene utilizes metallocene catalysts, nonmetallocenemetal-centered, heteroaryl ligand catalysts, late transition metalcatalysts, and combinations hereof.
 42. The blend of claim 41, whereinthe bulk homogeneous polymerization process for the isotacticpolypropylene utilizes a non-coordinating anion activated metallocenecatalyst system.